Jamie Fahey: Now you know your popular orange vegetables from your war-torn republics, can you work out what these phrases refer to?

UK research identifying loss of key protein in mice eggs is seen as a breakthrough that may help prevent birth defects

Scientists have made a breakthrough in understanding why older women become less fertile, suffer a miscarriage or have a baby with Down's syndrome.

The discovery could ultimately lead to treatments that would increase the chances of a successful pregnancy for growing numbers of would-be mothers in their late 30s and early 40s.

Researchers led by Dr Mary Herbert, an expert in reproductive biology at Newcastle University's Institute for Ageing and Health, have identified why some older women produce abnormal eggs, according to findings published in the journal Current Biology.

It has been known for a long time that would-be mothers who are nearing the end of their fertility are at higher risk than usual of having eggs that are affected by chromosomal abnormalities, but the underlying cause has been unclear.

The new study has identified problems arising from a woman's declining stock of proteins called Cohesins, which act as binding agents to hold chromosomes together by keeping them inside a ring. They are vital to ensure that chromosomes split evenly when cells divide.

Women's supplies of Cohesins fall as they age, Herbert and her colleagues discovered. Tests on eggs taken from both young and old mice indicated that the amount of Cohesins in women's bodies declines after their mid-30s.

When that happens it means that chromosomes are less tightly held together and they are therefore more likely to result in defective eggs, which can cause problems such as miscarriage and Down's syndrome.

Every cell in the human body, apart from eggs and sperm, contains two copies of each of the body's 23 chromosomes. Sperm and eggs must lose one copy each as they prepare for fertilisation. That process involves a complicated form of cell division.

This problem is compounded with eggs, because the attachments that hold chromosomes together have to be maintained by Cohesins until the egg divides just before ovulation.

When Herbert's team studied chromosomes during division in the egg, they found that the lower levels of Cohesin in eggs in older females led to some chromosomes becoming trapped and unable to divide properly.

"Reproductive fitness in women declines dramatically from the mid-30s onwards. Our findings point to Cohesin being a major culprit in this", said Herbert. More work was needed to understand why Cohesin declines over women's reproductive years, and such knowledge could lead to ways being developed to stop that loss from occurring.

Dr Peter Bowen-Simpkins, the medical director of the London Women's Clinic network of private fertility clinics and spokesman for the Royal College of Obstetricians and Gynaecologists, said the study was "very exciting" and could lead to real improvements in older women's chances of having children.

"This breakthrough could mean the difference between success and failure – them having a baby or not – for the fast-growing number of women who are trying to conceive after their late 30s," he added.

• Reproduction
• Biology
• Fertility problems
• Genetics

Lord Sacks accuses astrophysicist of logical fallacy in book excluding possibility of supernatural creation

The chief rabbi, Lord Sacks, hit back at Stephen Hawking after the astrophysicist said God did not create the universe.

In his new book, The Grand Design, published next week, Hawking concludes that science excludes the possibility of a deity and that it is unnecessary to "invoke God to light the blue touch paper and set the universe going".

But his finding were described by Sacks as an "elementary fallacy" of logic.

Writing in the Times, the chief rabbi said: "There is a difference between science and religion. Science is about explanation. Religion is about interpretation. The Bible simply isn't interested in how the universe came into being."

Sacks also said the mutual hostility between religion and science was one of "the curses of our age" and warned it would be equally damaging to both.

"But there is more to wisdom than science. It cannot tell us why we are here or how we should live. Science masquerading as religion is as unseemly as religion masquerading as science."

In an earlier book, A Brief History of Time, Hawking was apparently more open to the idea of God, suggesting that a scientific understanding of the universe was not incompatible with a creator. "If we discover a complete theory … it would be the ultimate triumph of human reason – for then we should know the mind of God," he wrote.

• Stephen Hawking
• Physics
• Religion

The problem extends beyond grumpy newspaper editors – it seems our psychology demands bad news about youth

Here's a sentence you won't read every day: "The vast majority of young people in London are a real credit to their local communities." These are the words of Richard Taylor, father of murdered 10-year-old Damilola Taylor. He was seconded by Olympic medallist Natasha Danvers, as they jointly launched the Pride of London awards in Damilola's name. "London has got a bad rap for youth crime," Danvers said. "But we should do a lot more to highlight all the good things young people here are doing because some of them are putting us adults to shame with what they are achieving."

I wholeheartedly agree, and so does the evidence. This week a report from the Jack Petchey Foundation painted an unfamiliar picture: 75% of young people regularly volunteer to help others, and most have values far removed from the fame-and-fortune obsession normally attributed to the X-Factor generation.

You're unlikely to have read about these remarks or findings in any newspaper, however. According to Google, not a single national has reported either story. With perfect timing, one of the reasons for this wall of silence may have been revealed by an intriguing new psychological study.

Silvia Knobloch-Westerwick of Ohio State University gave 276 volunteers an online magazine to browse. She found that older people preferred to read negative news about young people, rather than positive news. What's more, those older readers who choose to read negative stories about young individuals receive a small boost to their self-esteem as a result. Younger readers, in contrast, prefer not to read about older people at all.

The study was designed to test social identity construction theories, and the author believes it demonstrates that we use media to "enhance our social identities". Jargon-busted, she seems to be suggesting that in a youth-obsessed world, older people revel in a moment of smug satisfaction whenever they are reminded of the failings of youth. You might think the theory sounds speculative, and I might tend to agree, but the main finding certainly rings true.

We gravitate towards information that confirms our opinions, and tend to avoid that which will undermine or challenge us. It is just one of the many examples of cognitive biases at play in decision-making and judgment. Having our prejudices confirmed makes us feel better about ourselves, that is why we get the gleeful urge to say "I told you so". This study may be most revealing because it does not demonstrate a general schadenfreude, but a one-directional, specific effect that should give us pause to think about the media's coverage of young people.

Newspaper editors generally know who their customers are and what they want to read, and this research supports the argument that the media tend to over-report bad news about young people, and under-report the good.

Few would argue that modern youngsters get more bad press than any generation in history. The debate is about whether or not that bad press is deserved, and those arguments have been well rehearsed. With my journalist's cap on, I understand why sensational stories sell – if it bleeds, it leads. One horrific murder is more newsworthy than a million everyday good deeds. Yes, some young people have real problems, and some of them cause real problems. When one in four adults say they will cross the road to avoid young people, something has gone badly awry.

Of course there is little point calling on the British press to exercise restraint. As a package they are as self-righteous, stubborn and belligerent as any roomful of teenagers. It falls to us as readers to bear in mind that in this context, as in so many others, we may be manipulated in our understanding of the world, not just by mendacious or vindictive media reports, but by our own inescapable psychology.

• Young people
• Psychology

If the biggest technological leap since the Industrial Revolution is to benefit us all, governments and educators have work to do

The prefix "nano" is gaining an increasing presence in public consciousness, from invocations of the nanometre (nm) as a unit of measurement for our burgeoning silicon technology's tininess (as in Intel's latest 32nm processors), to the hubristically named iPod nano, which is a bit smaller than the others. The prominence of this word in our culture is set to rocket over the coming decades as more tightly defined "nanotechnology" becomes available – for example, Nokia is hoping to release a nanotech phone that it calls the Morph in 2015.

A commonly accepted definition of nanotechnology is that it deals with devices smaller than 100nm in size. A nanometre is one billionth of a metre. A single atom is between a tenth to half a nanometre across; a million or more of them stacked on top of one another would equal the thickness of a piece of paper. Nanotech machines will use individual atoms and molecules as mechanical moving parts, and will enable us to take apart and rebuild just about anything atom by atom.

If this sounds like science fiction, consider that you're carrying trillions of proofs of concept around inside you that could only be viewed with an electron microscope; every time your DNA is transcribed into RNA, or your muscle cells use fuel from food for movement, or your immune system fights off an infection, the work is done by nanomachines – devices built out of atoms and molecules which do mechanical work.

In his book, Engines of Creation, K Eric Drexler reminded readers that every manmade and natural object around us is an arrangement of (mostly very common) atoms and molecules. The ability to arrange those molecules more regularly will allow us to build materials many times stronger and lighter than those used in engineering today. This could bring a space elevator within reach, allowing us to explore the solar system and exploit the resources of the planets and asteroids cheaply. In the body, nanomachines could fight disease, or even aging, one atom at a time, restoring them to the configurations characteristic of healthy tissue.

An advanced nanotechnology would be capable of repairing the damage we have done to our environment, capturing carbon out of the air and salting it away under the earth, or using it to build the light, strong, diamond-like materials the nanotech-enabled human-scale technology will depend on. Ultimately, the most basic and useful elements we will need (carbon, oxygen, hydrogen, nitrogen, etc) can be harvested out of the air and dirt, and assembled into useful configurations with barely an hour of work. Nanotechnology has the potential to build a post-scarcity material economy – with the same implications we are so awkwardly working through in the post-scarcity information economy.

Drexler didn't shy away from confronting the negative possibilities of uncontrolled nanotech development in his book, and he and other scientists, such as those at the Centre for Responsible Nanotechnology, attempt to raise public awareness of the coming developments, which will inevitably grow out of research into molecular biology and computing (specifically, artificial intelligence and computer-aided design).

There are many terrifying possibilities for nanotechnology; military nanomachines could infiltrate human bodies and systematically tear them apart using the same principles medical nanomachines will use to repair them. An uncontrolled nanomachine designed to replicate itself could lead to the "grey goo" scenario that once panicked Prince Charles. Monopolistic practices on the part of the corporation or government that first produces a workable nanotechnology could hoard its benefits for one segment of the population, denying the rest of the world the massively increased prosperity it offers.

The solutions will have to complement one another if this, the biggest technological leap forward since the Industrial Revolution, is to benefit everyone. The most important is collaboration and diplomacy; the democracies that lead the world in scientific research need to collaborate in development and come to agreements that will share benefits and severely restrict weaponisation. Nanotech treaties will have far greater import for the survival of mankind, and of Earth as an ecosystem, than any nuclear treaty. Even "rogue" states need to be included in these efforts, simply because the new technology will be so desirable that if they are not included, they will push forward with their own, more dangerous and less controlled research.

The other aspect of preparation is education. The electorate need to be adequately informed to understand the debate that will take place and to put pressure on their leaders to choose the right paths. This means that formal science education in schools needs continued support from the ministers setting curriculums, and higher education and research needs support and funding so that we continue to have scientists and engineers capable of contributing to research and to public debate.

We need a forum for discussing the implications and direction of technological change in a way that is open and comprehensible to the public, and whose conclusions and advice ministers take seriously and do not dismiss on ideological grounds. Drexler proposes that such a forum needs the credibility of due process present in a court of law, and the scientific reliability that stems from peer review. Most of all, we need politicians with the courage to resist the temptation to short-termism that comes with limited terms in office, who realise that the debates arising in the coming years will see them legislating the shape of the future.

• Nanotechnology
• Science policy

For centuries scientists routinely straightened the tails of Mosasaur fossils in their reconstructions. But a recent re-examination changed overnight the way they see the sea-going lizards

Brian Switek blogs at brianswitek.com

On 6 April 1821 – a little more than two decades before their countryman Richard Owen would coin the term "Dinosauria" – the English naturalists Henry de la Beche and William Conybeare presented a report on a peculiar group of fossil animals to their fellows in the Geological Society of London. One of the subjects of their paper, the long-necked marine reptile Plesiosaurus, made its academic debut that night, but the others were already familiar to the scholars in attendance. Called Ichthyosaurus, these fossil creatures seemed to have been cobbled together out of equal parts fish and crocodile, and even during this era of pre-evolutionary palaeontology, de la Beche and Conybeare could not help but place Ichthyosaurus in what they believed to be a graded series of forms between fish, the newly discovered Plesiosaurus, and crocodiles.

At the time of their report, de la Beche and Conybeare did not have much to work with. Popular accounts of the marine reptile had made Ichthyosaurus famous, yet a significant portion of its skeleton remained unknown. The tireless efforts of one of the first expert fossil collectors – Mary Anning, of "She sells seashells on the seashore" fame – provided naturalists with more complete specimens, showing the various species of Ichthyosaurus to be crocodile-like reptiles with straight, tapering tails. Restorations remained true to the animal's "fish lizard" moniker, and when Richard Owen examined an Ichthyosaurus with a kink in the distal part of its tail, he came up with a series of scenarios by which the tail of the dead individual may have become bent. (My personal favorite: that part of the tail had become bloated with gas during decomposition and pulled the spinal column out of place.)

But Owen, as well as the various scientists and artists who had reconstructed Ichthyosaurus with a straight tail, was wrong. Exceptionally well-preserved ichthyosaur specimens discovered in the 1890s from Holzmaden, Germany, exhibited dark-coloured "halos" – created by bacteria that ate away at the carcasses as they laid on the bottom of the Jurassic seas – which represented the body shapes of these animals. Not only did Ichthyosaurus have a fleshy dorsal fin, but the downward tailbend was not a pathology – it was a normal feature which supported a large tail in the shape of a crescent moon.

Re-examined in this light, it became clear that even specimens preserved without soft-tissue impressions had vertebrae near the end of their tails that were wider at the top than at the bottom; a sure sign of a downward-kinked tail that supported a large caudal fin.

The image of Ichthyosaurus changed overnight. The piscivorous predator was not a big amphibious lizard with paddles where its hands and feet should be; it was a streamlined, fusiform creature which more closely resembled a shark than any lizard. By the close of the 19th century, the issue was settled, but spectacular specimens continue to change what we thought we knew about prehistoric life.

One such skeleton, found in the middle of Kansas in the 1960s, sat in storage for years, but a re-examination has caused scientists to reconsider what they thought they knew about another marine reptile – a mosasaur called Platecarpus.

Many books and documentaries cast mosasaurs among the many "also-rans" that lived alongside the dinosaurs between 98 and 65 million years ago.

A genus or two – usually Mosasaurus and Tylosaurus – get mentioned now and again, but the larger swath of mosasaur diversity is rarely elucidated. These marine reptiles, which were much more closely related to today's Komodo dragons than any dinosaur, were the fiercest predators of the Cretaceous seas, with many species occupying a range of habitats from near-shore to the open ocean. Most were not streamlined speed hunters like the ichthyosaurs, but instead looked like seagoing lizards; they were ambush predators that propelled themselves out of their hiding places with their long tails.

Among the most common of these marine predators was the species Platecarpus tympaniticus (named by the notorious "bone sharp" Edward Drinker Cope in 1869), and one century after it was first described an unusually complete specimen was collected from the well-known Niobrara Chalk in Kansas – a formation representing a time when a shallow sea covered much of western North America.

Shortly after it was excavated in the 1960s, the Platecarpus skeleton (known as LACM 128319) was stored in the collections at California's Natural History Museum in Los Angeles County. For one reason or another, it sat there, undescribed for decades, but in August of this year a team of palaeontologists led by Johan Lindgren of Sweden's Lund University at long last published a report on the specimen in the journal PLoS One.

Not only did it retain traces of soft tissues – including skin impressions and a reddish residue on its ribs that may be the remnants of its heart or liver – but its tail contained a distinctive set of vertebrae that were wider at the top than at the bottom. Platecarpus, just like Ichthyosaurus, had a downward-kinked tail that probably supported at least a modest tail fin.

Specimen LACM 128319 was not the first mosasaur skeleton to show signs of a tail fluke. In 2007, Lindgren led a different set of colleagues in describing the skeleton of a specialised form of mosasaur found in California called Plotosaurus (a specimen of which has also been found sporting soft-tissue impressions). The end of its tail sported a modified portion of vertebrae that looked extremely similar to the tail arrangement of sharks (just flipped down inside of up).

Along with a streamlined body that was deep from top-to-bottom, Plotosaurus was a mosasaur adapted to cruising in the open ocean – it was a mosasaur built like an ichthyosaur.

The skeleton of Platecarpus was not as specialised for pelagic life as that of Plotosaurus, but the examination of the new specimen shows that it was an intermediate form between the early, lizard-like mosasaurs and the last, highly streamlined types.

What is curious, however, is that the new specimen of Platecarpus represents yet another case of a marine reptile that independently evolved a downward tailbend. Ichthyosaurs did, some seagoing crocodiles (such as Geosaurus) did, and now we know that some mosasaurs did. Putting this in an even wider context, sharks have the same kind of tail, but their spinal column kinks upward and the fleshy part of their tail is below. In marine reptiles it is the other way around – with the spinal column bent downward – and perhaps there is some kind of shared evolutionary constraint, inherited from their last common ancestor, that caused the tails of marine reptiles to consistently bend downward when evolving this kind of propulsion.

As yet, such an evolutionary constraint has not been identified, but if it could be discerned, such a quirk of natural history might help us better appreciate how contingency and constraint shape evolution's grand pattern.

Brian Switek blogs at brianswitek.com

• Dinosaurs
• Fossils
• Evolution
• Biology

In a new book, world-renowned physicist Stephen Hawking argues that the universe is the work of physics, not God. Do you agree?

These stunning images from August include Moscow covered in smoke, heavy rains in Pakistan and plankton blooms changing the colour of the North Atlantic ocean

Research in The Lancet warns that existing medical practice does not work and may cause brain damage

Doctors should stop giving newborn babies sugar to relieve the pain of minor medical procedures because it does not work and may damage their brains, new research in The Lancet warns today.

The study says that small doses of oral sucrose do not reduce the pain which a baby feels when its heel is pricked to yield a blood sample or it has a drip put in to receive antibiotics.

Its conclusions directly challenge existing medical practice. Infants are routinely given tiny amounts of sugar in hospitals, both in the UK and around the world, as a way of limiting the pain they feel when they undergo short but painful procedures. Sick babies who receive sustained treatment in the early weeks of their lives may receive many doses to help them cope with repeated invasive procedures, which also include having an injection or having blood taken from a vein.

"Our findings indicate that sucrose is not an effective pain relief drug. This is especially important in view of the increasing evidence that pain may cause short and long-term adverse effects on infant neurodevelopment," said Dr Rebecca Slater, who led the Medical Research Council-funded study at University College London. "While we remain unsure of the impact sucrose has, we suggest that it is not used routinely to relieve pain in infants without further investigation."

Babies are usually given a dose of one-tenth of a gram of sucrose, a concentrated sugar solution, into their mouths before a procedure starts because doctors believe that it reduces, but does not remove, the pain involved. Many previous studies have found that the practice works, including a review of all the existing medical literature on it published earlier this year by the authoritative Cochrane Review.

But those studies were flawed because they relied on the change in the baby's facial expression upon receiving the sugar, from puckered-up to relaxed, as proof that it works, the new study says.

Instead, using different ways of measuring babies' reactions to the procedures, it has found that infants continue to feel pain, despite receiving the substance, as shown by measurements of the levels of pain activity in their brains and spinal cords after 59 newborns had undergone a routine heel prick test. Examination of the babies' leg reflexes also indicated that they felt discomfort despite receiving the sugar.

Neena Modhi, a professor of neonatal medicine at Imperial College London and a vice-president of the Royal College of Paediatrics and Child Health, said: "This is an important study. Sucrose is given because it seems to work. If it's confirmed that sucrose doesn't work, we have a problem because we don't have any effective treatments for acutely painful procedures in newborns."

But Modhi added that a bigger study, involving more babies, was needed and drug companies should speed up the development of treatments .

• Medical research
• Children
• Health
• Doctors

• Physics, not creator, made Big Bang, new book claims
• Professor had previously referred to 'mind of God'

Poll: Is Hawking right?

God did not create the universe, the man who is arguably Britain's most famous living scientist says in a forthcoming book.

In the new work, The Grand Design, Professor Stephen Hawking argues that the Big Bang, rather than occurring following the intervention of a divine being, was inevitable due to the law of gravity.

In his 1988 book, A Brief History of Time, Hawking had seemed to accept the role of God in the creation of the universe. But in the new text, co-written with American physicist Leonard Mlodinow, he said new theories showed a creator is "not necessary".

The Grand Design, an extract of which appears in the Times today, sets out to contest Sir Isaac Newton's belief that the universe must have been designed by God as it could not have been created out of chaos.

"Because there is a law such as gravity, the universe can and will create itself from nothing," he writes. "Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist.

"It is not necessary to invoke God to light the blue touch paper and set the universe going."

In the forthcoming book, published on 9 September, Hawking says that M-theory, a form of string theory, will achieve this goal: "M-theory is the unified theory Einstein was hoping to find," he theorises.

"The fact that we human beings – who are ourselves mere collections of fundamental particles of nature – have been able to come this close to an understanding of the laws governing us and our universe is a great triumph."

Hawking says the first blow to Newton's belief that the universe could not have arisen from chaos was the observation in 1992 of a planet orbiting a star other than our Sun. "That makes the coincidences of our planetary conditions – the single sun, the lucky combination of Earth-sun distance and solar mass – far less remarkable, and far less compelling as evidence that the Earth was carefully designed just to please us human beings," he writes.

Hawking had previously appeared to accept the role of God in the creation of the universe. Writing in his bestseller A Brief History Of Time in 1988, he said: "If we discover a complete theory, it would be the ultimate triumph of human reason – for then we should know the mind of God."

Hawking resigned as Lucasian Professor of Mathematics at Cambridge University last year after 30 years in the position.

• Stephen Hawking
• Physics
• Religion
• Science and nature
• Creationism

Bjørn Lomborg's change of mind on climate change is welcome, and some of his suggestions good, but your glowing review of his new book failed to examine deeply his shift in position (Top climate sceptic calls for $100bn fund to fight warming, 31 August).

Dr Lomborg last year began to call for an investment of $100bn per year on research and development for low-carbon technologies, instead of the $25bn he was advocating 18 months ago. He now proposes that this should be raised through a carbon tax of $7 per tonne of carbon dioxide, rather than the $2 per tonne for which he previously argued.

However, his strategy is alarmingly risky – invest heavily in R&D and hope that this alone will keep atmospheric concentrations of greenhouse gases low enough to avoid the risk of serious and damaging impacts from climate change. This might work, but it might not.

A more robust approach to managing the risks of climate change would be not only to invest in R&D, but also to use a carbon tax (or cap-and-trade) to discourage greenhouse gas emissions in the short run. The latter, not raising revenue, would be the primary purpose of introducing a carbon price. But to encourage enough emissions cuts in the next few years to keep greenhouse gases at low enough atmospheric concentrations, a carbon price considerably higher than Dr Lomborg's $7 per tonne is required.

We welcome the fact that Dr Lomborg has implicitly acknowledged that his previous arguments about climate change were flawed, but it would be wise to remain wary of his pronouncements, no matter how much publicity they attract.

Dr Alex Bowen, Dr Simon Dietz, Dimitri Zenghelis and Bob Ward

Grantham Research Institute on Climate Change and the Environment, LSE

• What might be of equal surprise to Bjørn Lomborg's "U-turn" is that there are practical solutions available to raise the money that is needed without dipping into cash-strapped treasuries. A Robin Hood Tax on banks, levies on shipping and aviation emissions, money raised from the auctioning of emissions allowances from emissions trading schemes and redirecting fossil fuel subsidies are all realistic options.

Environment ministers from around the world meeting in Switzerland today must consider these options if the world is to move closer to a financial solution in tackling climate change and protecting poor people who are already vulnerable. Meanwhile, the shipping industry, which has faced no restrictions to its emissions so far, must begin to play its part by agreeing to a shipping levy when the International Maritime Organisation meets in London on 27 September.

Phil Bloomer

Campaigns and policy director, Oxfam

• I note with interest that Bjørn Lomborg has changed his mind on global warming. I also note that he has a book to sell.

Rod Shone

Walkern, Hertfordshire

• Climate change
• Climate change scepticism
• Carbon emissions
• Climate change

Our consciousness paves the way for our spirituality, but there's little consensus

In finger-wagging style, Mary Midgley warns that "serious scientists know that their enquiries are endless; any answers always raise a swarm of new questions" (Serious scientists know that they cannot explain all the major puzzles of existence, 28 August). But who ever said otherwise? Well, I did apparently.

She quotes from my 1995 book, Soul Searching, selecting passages to back her assertion that I believe that science can provide "a sufficient explanation for everything that is or might be". What she fails to say is that in these passages I was describing how things looked to overconfident natural philosophers at the end of the 18th century, and how this set the stage for a Romantic reaction and in particular for spiritualism and psychical research.

True, I wrote that "two hundred years later this ambitious [Enlightenment] programme for a self-sufficient science has succeeded beyond the dreams of its inventors. Across great swaths of nature ... the major puzzles of existence have been pulled to pieces in the hands ... of all-conquering and -consuming scientific rationality."

But I went on: "Yet equally, two hundred years later, the majority of ordinary people have remained as faithful as ever to the earlier ways of thinking." And this was precisely my point. For most people scientific explanation remains unsatisfying. Indeed almost everybody has a Midgley – and a Newton – inside them, protesting that there has to be more to life, the universe and everything than we can ever know.

Midgley asserts: "Humphrey is convinced that something called science has indeed solved the mind-body problem." But if she had read further she would have found me saying: "All but a few contemporary psychologists agree that there will eventually prove to be some sort of satisfactory theory of mind-brain relationship … But at present there really is very little consensus about the form, let alone the substance, of this theory-to-come."

However, Midgley, it seems, has no interest in such a scientific theory anyway. For her, "our problem here is to understand the relation between our inner and outer life … and how to face life as a whole". Strangely enough, I entirely agree. In my own more recent writing, such as Seeing Red, I have begun to argue that the explanation for why consciousness evolved lies in its very mysteriousness and the effect this has on our world-view.

Since Midgley has quoted at such length from a book I wrote 15 years ago, let me answer with these words from the cover of my new book Soul Dust: "Consciousness, [Humphrey] argues, is nothing less than a magical-mystery show that we stage for ourselves inside our own heads. This self-made show lights up the world for us and makes us feel special and transcendent. Thus consciousness paves the way for spirituality, and allows us, as human beings, to reap the rewards, and anxieties, of living in what Humphrey calls the 'soul niche'." I invite Mary Midgley to review it.

• Religion
• Philosophy
• Atheism
• Controversies in science

With the BBC now providing links to the scientific research it reports, will 2010 be the year when science journalists discover the web link?

It's funny how things can be connected. I was looking up the recipe for Worcestershire sauce last night and ended up idly clicking through Wikipedia. It turns out that the sauce is made from anchovies, which can cause amnesic shellfish poisoning, a brain-damaging illness that may have caused thousands of frantic seabirds to invade towns in Californian in 1961; events that may have provided some inspiration for Hitchcock's film The Birds. I found all this because of links.

Links are the foundation of the world wide web. They take us beyond whatever we happened to be looking for, on journeys to places we never even imagined existed. Every minute of every day, millions of curious apes click billions of links, each travelling on their own miniature voyages of discovery.

Of all the differences between science blogging and mainstream media reporting of science, one of the most profound is the use of links. Science bloggers often come from a scientific background, and as scientists we were drilled on the need for citations. Any factual statement or assertion you make in a research paper should be backed up with a reference to primary evidence supporting the claim.

It's a habit that translates well into journalism, a profession which, like science, should be concerned with studying the world and reporting its findings on behalf of the public in an open and accountable way.

By providing links to sources (or indeed posting full interview transcripts), journalists can show that they're honest, open and trustworthy and allow the reader to judge whether the interpretation they've presented of someone else's work or words is the correct one.

And links can do much more than that. By embedding links in text, journalists can turn their articles from static descriptions of the world into platforms that open up avenues for exploration and discovery to their audience, tapping into rich veins of knowledge and intrigue to provide the reader with far more value than one journalist could provide on their own.

Links are beautiful, so why are newspaper websites so utterly reluctant to use them? In particular, why do science journalists who write about scientific papers so often fail to provide a link to a copy of the paper in question?

It's an issue that Ben Goldacre raised with the BBC earlier this year, but with apparently little success. As Ben pointed out at the time:

"It's very important that the public are able to get access to information, especially since media reports – for many structural reasons – can be light on information, or even contain errors."

But now the Beeb seems to have relented. It has come to my attention, courtesy of the commenter soveda, that the BBC are – occasionally at least – now adding links to the original research in their articles, for example in the 5th paragraph here.

This is to be congratulated. It's easy to moan when journalists get things wrong, but fair play to the BBC here – they've listened, and they appear to have changed their practice. For that they should be congratulated, and if you give a crap about news outlets linking to research (and if not, why on Earth are you still reading this?) then you should go immediately to their feedback page, and leave a friendly comment.

So will other organs follow the BBC's lead? Unfortunately, the scientific journals themselves are putting barriers in the way of journalists who want to link to the original research, as the science editor of the Times Mark Henderson told me earlier:

"I think it's good practice to provide direct hyperlinks to journal articles where practical, but this isn't always easy to achieve. The main problem is that while some journals (eg Nature) provide such links on their embargoed press releases (or tell you how to work them out using DOI numbers), others do not. It can thus take time you don't have to establish the correct link.

Worse still is that some journals (PNAS is a particular offender) don't have papers available online when an embargo lifts. It is thus impossible to link even to an abstract."

Embargoes themselves are a difficult and controversial subject best left to the likes of Ivan Oransky, but clearly there's a problem with the way that PR officers at some major journals are operating – by failing to support busy journalists, they're failing the public. One simple solution would fix this problem, as Mark suggests:

"I would encourage all press officers dealing with journal articles to include a hyperlink to the paper, that will go live when an embargo lifts, on their press releases as a matter of course."

Let's hope that the BBC's decision will start putting pressure on journals to do just this. But let's not forget the wider problem here. As blogs and mainstream media draw ever closer together – a long-term shift epitomised by my own move to the Guardian – there are opportunities for each to learn from the other. One of the most obvious things that bloggers can teach mainstream media journalists is the proper use of the link. It's not enough for journalists to simply report on the world, they need to let people see it for themselves.

Should our response to the rising number of sexually transmitted infections (STIs) be a call for more ignorance, as one MP appears to believe?

Woody Allen, in the movie Annie Hall, tells a joke about how two elderly (probably Jewish) women are at a Catskill Mountain resort, and one of 'em says, "Boy, the food at this place is really terrible." The other one says, "Yeah, I know; and such small portions."

That's how I feel about sex education in Britain's schools.

Over the bank holiday weekend, an MP, Stewart Jackson (Conservative, Peterborough) in response to media reports of a rise in the number of STIs (sexually transmitted infections) in teenagers, said on Twitter that the problem was too much sex education. He tweeted on 26 August:

V disappointing news on STD rates in Pboro. No doubt our liberal friends will tell us we need MORE sex education – as it's worked so well

Predictably (although perhaps not to Mr Jackson), when it was further circulated on Twitter it led to a flurry of comments from people agreeing and – mainly – disagreeing with him. As far as I can tell, at first he chose not to respond but after some time he lashed out on Twitter, saying:

Touched a raw nerve with shrill intolerant pro sex education Lefties who don't like debating the issues. Wonder why not?

On 27 August he said,

Re. Sex education Memo to sad tedious sex obsessed Leftie weirdos – do please tweeting me [sic] You're confusing me with someone who's interested

and then

Left are simply unable to debate issues without personal abuse and vicious shrill denunciation. Important we keep them locked out of power

The irony of tweeting an insult (even truly sad, tedious, sex-obsessed Leftie weirdos don't identify themselves as such) then complaining about insults led to a flurry of comment on Twitter, on blogs and even on the BBC.

On Twitter everyone's tweets are public and accessible and it seems that all the tweets that had been directed at Mr Jackson – all that the bloggers could find – are entirely civil (certainly by parliamentary standards) and seek to debate the issues. It is therefore hard to see what he was objecting to when he made his complaint on which he enlarged in the Peterborough Evening Telegraph, where he also said that:

"I wanted to engage in intelligent debate but was met with a barrage of crude, personal abuse. I am always keen to hear from my constituents but these people were generally not even from Peterborough and were only interested in making personal attacks."

This repeated assertion had all the ingredients needed to infuriate people who use Twitter – rather like poking a wasps nest – who felt not only that they were right (cue cartoon), that he was failing to engage with them, that he falsely or unfairly accused them, but also that they had caught him in that alleged falsehood. None of these blogs, except perhaps one, was particularly rude, as opposed to critical, and there is no evidence that they were emailed or tweeted to him.

There are some important issues behind all this.

First, it is not clear whether the rise in reported STIs reflects a genuine rise in incidence or is an artefact of more widespread testing (leading to more true positives being picked up). This has been covered by Mark Easton at the BBC and by Dr Petra Boynton, and no doubt elsewhere, so I will not pursue that further here.

Second, there is the question of whether we have too much sex education or too little. I would say we have too little and of poor quality. This is also the view of young people themselves, who report that sex education does not tell them what they need to know or does not reach them in time. There is surely merit in providing sex education before children are sexually active, and before the pubertal "giggle factor" and the "schoolyard fable factory" prevent information being readily accepted.

There is international evidence that "school-based sex education improves awareness of risk and ways to reduce it. It increases the intention to practise safer sex and delays rather than hastens the onset of sexual activity". There is also evidence of this from the UK.

Hell, sex education has even been reported to work in Peterborough!

Other countries seem to do it better (sex education that is). For example in the Scandinavian countries and Holland, which can hardly be described as puritanical, and where sex education is delivered early and clearly (and where the media is more supportive of it), the rate of teenage conception (and teenage abortion) is much lower than in the UK. The age of first intercourse is also delayed relative to the UK. It seems that providing information equips boys to resist peer pressure and girls better to resist boy pressure. It also makes the use of effective contraception more likely when sexual activity does begin.

I agree with Anne Widdecombe. I will repeat that. I agree with Anne Widdecombe – and Stuart Jackson – that there is a problem with the over-sexualisation of young people by our media more widely. I agree with them that this is unhealthy. No doubt it contributes to the earlier onset of sexual activity and also causes misery to girls (mainly) as they feel expected to conform to the sexualised body images portrayed in the media.

Given that this is the society we have (and it is impossible to uninvent the internet, movies, teen magazines, TV, etc) we have two approaches to tackling this problem that could be used in combination.

First, we can try to roll back the normalisation of portrayals of women as mainly or primarily sexual objects. We can for example regulate – or self-regulate – so that so-called family newspapers do not portray women in topless or sexual poses, and that such objectification and soft porn is marketed as such. So, for example, magazines like Zoo and Nuts should be available to adults and displayed and sold as such. I have supported cross-party campaigns on this led by the Fawcett Society and Object, but I am not certain whether Mr Jackson has done so.

Second, we can equip young people for the world as it exists rather than as we would wish it to be. The curious thing about those who believe in Victorian values is that the Victorian age was a golden era for the sexual exploitation of women and the abuse of children.

Jury in Terry Jupp inquest criticises risk assessment and communication in secret explosives tests that went fatally wrong

Secret explosives tests in which a blast killed a Ministry of Defence scientist were inappropriately planned and appeared to have been inadequately organised, an inquest jury found today.

The jurors made a number of criticisms of the trial, in which Terry Jupp was involved, at a testing station near Shoeburyness, Essex, in August 2002.

They concluded that planning and risk assessment had been inappropriate, that a small-scale test could have been carried out in advance, that adequate regard was not paid to personal protective equipment, and that communication and organisation at the trials appeared inadequate.

Jupp, 46, who worked for the MoD's Defence, Science and Technology Laboratory (DSTL), was involved in explosives tests aimed at combating terrorists in the months after the 9/11 attacks in the US, the inquest in Southend heard. Much of the hearing was held in secret to prevent the disclosure of sensitive information, and the chemicals involved in the fatal test were referred to only as A, B and C.

Jurors heard that Jupp and colleagues had just finished mixing the three chemicals when the explosion occurred. He suffered severe burns and died a week later in hospital.

The tests were part of joint experiments between British and US experts, the inquest heard. One witness said the results could be "catastrophic" if information about the testing fell into the wrong hands.

Jupp's widow Pat said she thought the jury had assessed the evidence correctly.

"I think the jury got it right," she said.

"I don't want anything like this to ever happen again."

She added that had never been able to discuss the sensitive nature of the work with her husband, and that listening to evidence about his death had been "extremely harrowing".

Pat Jupp said she felt satisfied by recommendations made for improvements following an inquiry into her husband's death.

"The Ministry of Defence have lost a highly experienced, loyal, dedicated scientist," she said.

"I feel very proud in the knowledge that he helped to save thousands of lives doing the research work that he carried out."

She said she felt the inquest had been a "fair and thorough" inquiry and she was "very pleased" with the outcome.

Any student willing to engage will get good value for money

The Browne review into the funding of higher education has led to a debate on whether a university education provides value for money. In the last three months, there have been two comment pieces by arts students complaining about the "paucity of teaching" within their degrees and suggesting that the disparity between arts and science contact hours should be reflected in the fees.

I'm entering my third year of a chemistry degree at the University of Manchester and I would not be surprised if, as a result of the Browne review, science undergraduates are asked to pay considerably higher fees without any real debate about whether they actually get more value for money than arts students.

Last year, my fees "bought" between 15 and 20 contact hours a week. Eight hours of lectures, nine of labs, along with regular tutorials and workshops. I got the chemicals I needed to run my experiments, the support I needed to do them safely and the journal subscriptions necessary to place my experiments in context. So far so good.

And what experiments did I do? The same standard set of experiments that were performed last year and will be performed next year. That's not a complaint; learning the basic techniques is an essential part of any science degree. But it does preclude original thinking; all my assessments to date have involved "right" answers that can be logically deduced from the available knowledge.

By comparison arts students, if they are lucky, get six to eight hours of lectures, seminars and tutorials a week. Instead of labs and workshops, they get extensive reading lists: they are "paying for the privilege of reading textbooks". So for three years and almost £10,000 in tuition fees, what do they really get?

Well, for one thing, they get a sounding board for their ideas. Once arts students have worked through their reading list, they're going to have ideas about what they've read and how these ideas fit into the grand scheme of things. At university, they get access to a knowledgeable faculty and, through discussions, can clarify and better express their ideas.

Their fees also pay for the supply and maintenance of the huge collection of books necessary to develop the required depth of knowledge – otherwise known as the library. It's a telling fact that at the main University of Manchester library, there is part of one floor devoted to science and nearly five wings devoted to the arts.

Another, more abstract, way of looking at value for money is by examining the skills learned through a degree. Again, arts students apparently don't get value for money. What do they learn? How to read a book? How to analyse a theme? Compare that to a science student who has potentially learned the basics of probing the nature of the universe.

Yet the majority of graduate entry jobs simply require a degree, irrelevant of specialisation, so there must be something valuable about an arts degree. All students are essentially taught the same skills; the ability to work self-sufficiently, a toolkit of problem-solving methods and the skills and confidence to apply it in unknown situations.

The more you put in to your degree the more you get out. Those who take the time to seek out lecturers and use all the resources their fees pay for get far higher value for money than those who simply cruise through. Also, whether you're studying 10th-century Norse poetry or the stereochemistry of heterocyclic molecules, degree-level study requires a stupendous amount of work to reach the standard required.

Arts and science degrees are different but equal, and equally valuable. So please, stop demonising science students because we spend more time in labs and less time in the library.

• University teaching
• Tuition fees
• Higher education
• Arts
• University funding
• Lecturers

Computer scientist urges software developers to help climate scientists produce better modelling tools. From BusinessGreen, part of the Guardian Environment Network

A study by a computer scientist at the University of Toronto suggests that the computer models used to predict climate change may be undermined due to a lack of programming expertise.

Steve Easterbrook at the University's Department of Computer Science, has had his paper, Climate Change: A Grand Software Challenge, accepted by the 2010 FSE/SDP Workshop on the Future of Software Engineering Research. In the paper, he suggests that because many climate prediction software modelling tools are built by climate scientists rather than software engineers some of the resulting software has room for improvement.

Climate scientists commonly use so-called Global Circulation Models (GCMs) that simulate the atmosphere, oceans, cryosphere and biosphere at a global scale, Easterbrook said. Underpinning them are data analysis tools designed to crunch the underlying numbers.

"Most of this software is built by the climate scientists themselves, who have little or no training in software engineering," said Easterbrook in his paper. "As a result the quality of this software varies tremendously: The GCMs tend to be exceptionally well engineered, while some data processing tools are barely even tested."

Easterbrook called for climate scientists to use applications written by experts in software design that would enable cross-disciplinary work to address climate change questions. These analysis tools would be proven capable of processing "earth models", he said.

Secondly, Easterbrook argued that information sharing systems, such as games, reputation analysis software, and crowdsourcing tools could help to disseminate information on climate change efficiently and responsibly.

Finally, he said that energy efficient green IT systems are needed to reduce power consumption in all areas where climate modelling software is used.

"A massive mobilisation of talent will be needed. Other disciplines are already developing disciplinary responses to this challenge," Easterbrook concluded. "It is time for the software community to step up to the plate."

• This article was amended on 2 September after Steve Easterbrook said the original headline - "Climate scientists should not write their own software, says researcher" - was inaccurate.

• Climate change
• Climate change
• Programming
• Computing

Just before this blog moved to the Guardian, I wrote about a supersymmetry meeting I attended. Now my theory pal who organised it chips in

In case you missed it, I wrote about a conference on supersymmetry I went to last week, just before this blog moved home. I also gave some reasons why supersymmetry might, or might not, be seen as an attractive extension of the Standard Model of particle physics, given that there is no experimental evidence for it yet.

Now my theory friend Herbi Dreiner, who I used to work with when I was a student and who organised the Bonn meeting, has given his view. Since I know there are heaps of supersymmetry fans out there, I thought I should bring it to your attention:

The conference on "Supersymmetry and the Unification of Fundamental Interactions", which my colleagues and I organised in Bonn, finished yesterday. The entire week I was thinking I would drop into bed and sleep for a full day. But oddly, I feel quite refreshed. It was great fun listening to the talks and discussing with so many friends and colleagues, despite all the organisational headaches. The conference dinner was on an elegant boat which in an earlier life was used for the signing ceremony of the Schengen agreement. (For us mainland Europeans this is a big deal.)

Supersymmetry seems alive and well and ready to face the challenge from the LHC. But what is supersymmetry? And what is so super about it? Why are we so taken with it, even though there is as yet no experimental evidence it actually exists? There are two main arguments. First, it is a solution to the "hierarchy problem". I will save this for a potential second post, if Jon invites me back. The other is indeed an aesthetic argument related to the "Coleman-Mandula theorem".

Now, I tell myself every morning in front of the bathroom mirror that aesthetics is for wimps, but it is all the same an interesting argument.

Symmetries have become a central pillar of our understanding of nature. A sphere is symmetric in the sense that if you leave me in a room with the sphere and come back in, you cannot tell if and by possibly how much and about which axis I have rotated the sphere. The sphere is highly symmetric. This, however, also makes a sphere kind of boring, since because it has to be the same in every direction it has no structure. If the sphere has a pattern on it, like for example an old black and white football, only very specific rotations are still undetectable. This is the remaining, reduced symmetry.

It turns out that in the world of elementary particles there are two types of symmetry. One kind is internal symmetries. These govern the forces of nature like the electromagnetic force. Here a hidden, internal property of particles is changed. The other kind we call external symmetries and they affect the way particles fly through space and time. The appropriate external symmetry is described by special relativity, invented by Einstein in 1905. The undetectable transformations are called Lorentz transformations. In this case the laws of nature are unchanged if we look at the particles for example on a stationary train or one moving with constant velocity (and on smooth tracks!).

Now how about Coleman and Mandula? They showed that in fact the Lorentz symmetries are the maximal external symmetry allowed in nature. If you were to introduce a larger more extensive symmetry the world would become so boring that particles could no longer interact. They would just fly around freely in space not knowing about each other.

However, in their argument Coleman and Mandula neglected one external property of particles, their spin. This is a peculiar quantum property: they behave as if they had a small internal magnet. In specific units all the matter particles we know, e.g. the electron and the quarks, have spin 1/2. The force carriers like the photon have spin 1. Spin is an external property, which is affected by rotations in space.

Now if we extend Coleman and Mandula and allow for discrete changes of spin by half a unit, we find a new maximal external symmetry of nature. This is supersymmetry. It is super because it goes beyond the previous external symmetries. If nature is supersymmetric the electron must have a partner with spin 0 and the photon a partner with spin 1/2 and all with many interactions.

However, if this symmetry were at all extended (now also taking spin into account, of course) the resulting world would be boring and trivial with no interactions. Since we have now used up all external particle properties we believe this is the end of the line. This is what makes supersymmetry so special ... and to some beautiful.

Of course, the data from the LHC over the next months and years, but also from precision measurements of certain particle properties, will decide whether any of this is real.

New research confirms that psychedelic drugs are promising treatments for depression, obsessive-compulsive disorder (OCD) and schizophrenia

Moheb Costandi writes the Neurophilosophy blog

Long before hippie poster boy Timothy Leary invited the world to "Turn on, tune in and drop out", a group of pioneering psychiatrists working in Canada began to treat alcoholics with lysergic acid diethylamide (LSD), and reported unprecedented recovery rates.

Far from being at the fringes of medical research, their work was fully supported and funded by the Canadian government, and became a promising new area of research that played a role in modernising the field of psychiatry. But despite the encouraging results, studies of LSD therapy ended abruptly in the late 1960s, and did not resume again until some 40 years later.

At the cutting edge of early psychedelic research was one Humphry Osmond (1917-2004), a British psychiatrist at the Weyburn Mental Hospital in the Canadian province of Saskatchewan. It was Osmond who gave the novelist Aldous Huxley his first dose of mescaline in 1953, and coined the term "psychedelic" in 1957.

Between the years of 1954 and 1960, Osmond and his colleague Abram Hoffer treated some 2,000 chronic alcoholics with LSD. None of these patients had responded to other treatments, and yet, Osmond and Hoffer reported that up to 45% of those treated with a single large dose of the drug abstained from drinking for at least a year afterwards.

Other researchers in Canada, Britain, the United States and elsewhere began experimenting with LSD therapy, and by the time the drug hit the streets in the early 1960s, there were more than a thousand published research papers that described promising results in over 40,000 patients.

These studies took place alongside trials of newly developed compounds such as the antipsychotic chlorpromazine and the tricyclic antidepressant imipramine. This body of work effectively established the new field of psychopharmacology, which led psychiatrists to abandon the psychoanalytical approach they had been using since the turn of the century, and begin to consider alcoholism and mental illnesses in terms of disrupted brain chemistry.

Although the results of many of the early studies into LSD therapy were promising, investigations of the potential therapeutic benefits of the psychedelic drugs stopped towards the end of the decade, for two main reasons.

First, some began to question the methods used in the studies, arguing that they lacked scientific rigour, and few, if any, other researchers managed to replicate the high recovery rates reported by Osmond and Hoffer. Many therefore viewed the early studies as providing nothing more than anecdotal evidence for the therapeutic benefits of LSD.

Second, and more importantly, the cultural and political climate became less conducive to psychedelic research. LSD became a popular recreational drug towards the end of the 1960s, and came to be associated with the hippie counterculture, anti-authoritarianism and social disobedience. As a result, research funding quickly dried up, and the drug was eventually criminalised by the US and other governments in 1970.

The past decade has seen renewed interest in the potential therapeutic benefits of LSD and other psychedelic drugs, and the availability of sophisticated techniques such as functional neuroimaging is beginning to provide fresh insights into how they affect the brain.

The new research confirms that the psychedelic drugs do indeed have therapeutic value for a number of psychiatric conditions, including depression, obsessive-compulsive disorder (OCD) and schizophrenia. It also points to various brain mechanisms which may underly their beneficial effects.

We now know that the so-called classical hallucinogens (LSD, psilocybin and mescaline) activate 5-HT2A receptors – which normally bind the neurotransmitter serotonin – in the deep layers of the prefrontal cortex. This in turn alters nerve cell signalling mediated by the transmitters glutamate and dopamine, and may also lead to changes in the strength of connections between neurons in the cortex and other parts of the brain.

Serotonin and dopamine convey messages in the brain circuits involved in mood, and psychedelic drugs apparently alleviate the clinical symptoms of mood disorders by modulating the activity of the cells in these circuits and by modifying their connections.

The very latest research shows that ketamine, an anaesthetic with hallucinogenic properties, can reduce the symptoms of depression quickly and effectively, and that MDMA (popularly known as ecstasy) can be beneficial to sufferers of post-traumatic stress disorder when used in combination with behavioural therapy.

By contrast, new research into the effects of the classical hallucinogens has progressed at a much slower pace, probably because these drugs are categorised as Class A in the UK (Schedule I in the US), and researchers who wish to obtain them therefore face numerous regulatory barriers.

Nevertheless, it now seems quite clear that psychedelic drugs have enormous potential for treating a wide variety of psychiatric conditions. Much still remains to be discovered about exactly how they affect the brain, however.

For example, optimising their clinical benefits will require a better understanding of how their molecular structures are related to their activity, and of how each drug can be combined with psychotherapeutic approaches to achieve the best results.

Furthermore, because most psychedelics can mimic the symptoms of naturally occurring psychoses – they can, for example, induce hallucinations and disorganised thought processes – future research may reveal some of the brain mechanisms underlying schizophrenia and related conditions.

The debate that occurred in the 1960s about the therapeutic use of LSD mirrors the one taking place today over the use of MDMA, so the history of LSD experimentation could provide valuable lessons about how to incorporate these controversial drugs into modern medicine.

Moheb Costandi is a molecular and developmental neurobiologist who writes the Neurophilosophy blog

Further reading
The secret history of psychedelic research (Neurophilosophy)
Serotonin, psychedelics and depression (The Neuroskeptic)
Ketamine for depression: yay or neigh? (The Neurocritic)
Visions of a psychedelic future (Mind Hacks)

Vollenweider, F. X. & Kometer, M. (2010). The neurobiology of psychedelic drugs: implications for the treatment of mood disorders. Nature Reviews Neuroscience; 11: 642-651.

•  Moheb Costandi writes the Neurophilosophy blog

• Drugs
• Psychology
• Medical research
• Biochemistry and molecular biology
• Chemistry
• Drugs
• Health
• Depression in adults

They're fried in fat and smothered in salt, but still we eat a heart-stopping 6bn packets of them a year. So why do we have an unhealthy obsession with potato crisps?

• Food blog: what's your favourite crisp?

In an unremarkable suburb of Leicester called Beaumont Leys is a big factory – or actually two, side by side. But let's not split hairs already. The point is that it's big; a winding 10-minute march from reception round to the delivery bays.

These bays are where the raw material comes in, which is potatoes. The variety changes with the season, depending on whether they've come straight from the fields in summer, or from storage during winter. There are Hermes, Saturna and, right now, round, pink-cheeked Lady Rosetta.

Let's follow her, briefly. She is washed out of the truck – shedding any small stones or vestiges of earth she may be clinging to – and carried by stainless steel conveyor belt to a spinning drum, where she's peeled of her reddish skin.

She then passes across an inspection belt, where practised human eyes beneath faintly ridiculous but absolutely obligatory hygenic hair-nets hunt out hidden blemishes. Then, razor-sharp rotating blades slice her into 1.3mm slivers of starch and water.

Next, the excess starch is washed away (or the slivers will stick together), and the excess water dried off (it plays havoc with boiling oil), and hey, it's frying time: three brief but, one can only imagine, intense minutes in a 5,400-litre tank at 180C.

Out come the slices, all curling and golden and smelling (believe me) very good, whereupon a fiendishly smart automated scanning device gives them all the once-over once more, shedding those that look less than perfect. Next it is into the big drum for seasoning, which you're not allowed to see because it's top secret. Then weighing and bagging (more smart machines), and that's it: in less than 20 minutes, Lady Rosetta has become a packet of crisps.

This doesn't, though, give a true impression of the grandeur of the whole operation. This factory, belonging to Britain's largest crisp manufacturer, Walkers, is the biggest crisp factory in the world. It processes 800 tonnes of potatoes a day. It has six, 200m-long production lines, each of which turns out three tonnes of crisps an hour. That's maybe 120,000 small 25g packets. Per hour. Times six.

And this is only one of Walkers's seven UK crisp plants. Between them, they produce 10m packets a day, satisfying just under half this country's appetite for potato chips.

In short, we eat an awful lot of crisps. They are a national obsession. Practically everyone has a favourite flavour, or an unexpected craving, while even those who don't like them feel strongly – worrying, as chef Jamie Oliver has done very publicly, that this very British habit is doing untold damage to the health of the nation, particularly its children.

And when you consider we get through an estimated 6bn packets of crisps and 4.4bn bags of savoury snacks a year – around 150 packets a person – you do wonder what our love affair with crisps is doing to us. Looked at by tonnage, we consume more crisps, crackers and nuts than any other European country.

Unsurprisingly, though, the people at the Walkers factory wax positively lyrical. "There is," says James Stillman, head of research and development, "the physical experience. The crunch, the smell, the taste, how the salt dissolves on your tongue, how the flavours develop in your nose. Take our Sensations Thai Sweet Chilli: put one in your mouth and think. There's a five-second journey going on there, but you won't get it unless you really think."

It is, claims Stillman, nothing short of an emotional experience – "there's a great deal of anticipation in opening a packet of crisps" – and if so, it's an emotion that a great many of us share. Hardly anywhere else in the world, with the exception of America, do people consume fried potato slices in the manner, the variety and the quantity that we do, with well in excess of 100 varieties to choose from.

Elsewhere in Europe, the potato chip is a savoury something served with an aperitif (a complement, say, to the olive). In Britain, it's a food in its own right, or, as the Savoury Snacks Information Bureau puts it, "indisputably an integral part of the British culture".

In fact, muses food writer Matthew Fort, who confesses to a love affair with crisps dating back to the days of Smith's Salt 'n' Shake: "Crisps are our olives. The continentals once had plain olive oil. Now there's extra virgin, single estate, first cold pressed, extra virgin single varietal first cold pressed – you name it. We used to have plain ready salted; now there's any number of flavours, as well as traditionally cut, individually hand fried and the rest."

Hardly anywhere else is it possible to walk into a supermarket, corner shop, newsagent, petrol station or pub and expect to see arrayed before you a dozen or more brands, styles, varieties and flavours of crisps including (seriously) Balti Curry, Steak & Ale Pie, Chargrilled Chicken, Chilli con Carne, Jalapeno & Coriander, Taw Valley Cheddar & Caramelised Shallots, Spaghetti Bolognese, Aloo Masala, Xtra Spice Buffalo Wing, Argentinian Steak and BBQ Kangaroo.

But despite such esoteric offerings, Walkers's – and the UK's – top five has remained unchanged for years: in descending order, Cheese & Onion, Ready Salted, Salt & Vinegar, Prawn Cocktail and Chicken. "We're creatures of habit," says Stillman. "We like what we like, but we occasionally like to experiment. At any one time, Walkers will probably have 15 flavours in the market: the first five are generally the same, the other 10 will be changing pretty much constantly."

In continental Europe, by contrast, you're basically stuck with plain or, for some reason, paprika. We, though, are besotted: when Walkers ran its Do us a Flavour competition last year, in which the nation was invited to invent a new crisp flavour, it received 1.2m entries (the most memorable suggestion, Stillman says, was Ear Wax). This year, in parallel with the World Cup, the company ran its Flavour Cup, "a celebration of national cuisines from around the world". The popular winner was English Roast Beef & Yorkshire Pud, confirming that at heart, we see the crisp as something uniquely, quintessentially British.

Except, of course, it isn't. Or at least, it probably isn't. The crisp was allegedly born in Cary Moon's Lake Lodge (or Lake House) restaurant in Saratoga Springs, New York, on 24 August, 1853, when a former tracker called George Crum, son of a Native-American mother and an African-American father, got fed up with a customer (who may, or may not, have been rail magnate Cornelius Vanderbilt) sending back his fried potatoes because they were too thick for his liking.

The third (or, according to some accounts, fourth) time this happened, Crum, enraged, sliced the offending solanum tuberosum into wafer-thin slivers, deep-fried and over-salted the result, and sent the dish out again hoping the guy would choke on it. But Vanderbilt (if it was he) loved them – you can't go wrong, tastebud-wise, with starch, fat and salt – and Saratoga Chips became a staple of the restaurant's menu.

(I say "probably not British", incidentally, because a recipe for "fried potato shavings" was reportedly printed in America as early as 1832, in a book based on an even earlier collection of recipes from England. There again, when the first confirmed sighting of native British crisps was reported, in 1913, they were being made in London by a man called Carter, who had supposedly stumbled across them in France. So who knows?)

Anyway. In 1920, Smith's Potato Crisps Company Ltd was formed in Cricklewood, north London, with Mrs Smith peeling, slicing and frying the potatoes in the garage and Frank Smith packing them into greaseproof bags (later with a pinch of salt in a twist of blue paper inside) and selling them across London from his pony and trap. The firm was so successful it had moved to new premises and hired 12 full-time staff before its first year was out.

The company ran into trouble in the Depression, however, undergoing the humiliation of being rescued by its Australian subsidiary. But hard times proved the start of something big and beautiful for Mr Henry Walker, a successful pork butcher in Leicester. In the years immediately after the second world war he was facing bankruptcy, as rationing saw his shops in Cheapside and Oxford Street, London, cleared of meat before 10am, with nothing left to sell.

"It was a choice between ice-cream and crisps," former managing director Gerry Gerrard told the Leicester Mercury years later. He went for crisps because of the difficulties of handling meat and dairy products together. Walkers began in 1949 above the Oxford Street premises, with a staff of eight and Gerrard himself as head cook. The crisps were hand cut with a vegetable slicer, cooked in a chip-shop fryer, sprinkled with salt and sold for thruppence a packet under the slogan Potato Crisps by Walkers: Guaranteed Absolutely Pure.

They went down a bomb, and Walkers – which long ago swallowed Smith's, and is now part of the mammoth PepsiCo conglomerate – never looked back (helped in no small measure, since 1994, by the inspired choice of local lad Gary Lineker to front its advertising campaigns). We're no closer, though, to knowing why crisps are so big in Britain. What makes us, and so few others, so peculiarly partial to the potato chip?

There are plenty of theories. For Fort, it's mostly down to our unique relationship with the potato. "The potato has iconic status in this country; it's a subsistence food," he says. "A love of the potato is hard-wired into our gastronomic DNA. Plus, we've always been a grazing, snacking culture – look at our eating opportunities, we have more than anyone else: breakfast, elevenses, lunch, tea, high tea, supper, dinner . . . The French, the Italians, the Spaniards, eat twice a day, max. They're not snackers. The crisp is the perfect food for us."

Stillman reckons it has a lot to do with our high consumption of sandwiches, for which crisps are "an ideal complement", and of beer (ditto): "The creaminess of the potato, the salt and sweetness of the flavouring, the bitter of the beer; it all works." Felicity Lawrence, author of a brace of deeply scary books on the darker side of Big Food, also thinks pubs have something to do with it, but believes the underlying reason is that Britain industrialised earlier than most of the rest of Europe.

"Other countries maintained a more direct connection with their food and the land," she says. "We've been producing processed food for much longer, and consuming it too – there was a need for fast food from a very early stage, because people were working long hours in the factories." The crisp, then, is one of the earliest and most successful products of the long and happy marriage between industrialised food and a cheap, abundant crop.

Although the spectacularly competitive British market (remember Golden Wonder?) has been evolving and expanding pretty much since the crisp first arrived, aficionados point to two key revolutionary events: game-changing moments. The first was in the late 1950s, when years of kitchen experimentation by the late Joe "Spud" Murphy, proprietor of the cunningly named Tayto crisp company in Ireland, culminated in the invention of what is generally (though not, crisp history being a much-disputed field, universally) agreed to be the world's first crisp seasoning: Cheese & Onion.

The second major event was the arrival on these shores, in 1987, of an Oregon businessman called Cameron Earl, who brought with him a concept known as the Kettle Chip: thick, gnarled, irregular, crunchy, authentically flavoured and (naturally) more expensive. This was the premium product the hitherto classless world of the crisp had been waiting for, and it wasn't long before we saw an array of home-grown, artisan-inspired, hand-fried, organic rivals: Tyrrells, Burt's, Piper's and the rest. Walkers jumped in, too, with Sensations.

These are mostly known as "sharing" crisps, because they're sold in bigger bags, for more sociable consumption, and they're changing the shape of the market and the way we eat crisps. "They're for sitting on the sofa watching The X Factor," says Stillman, "not munching with your lunchtime sandwich." Sales of individual packets are falling slowly as sales of sharing packets, worth £370m last year, rise.

A posher product image, though, does not make for an inherently healthier product. Sharing crisps are almost all still cooked in fat and sprinkled – most of them – with salt (albeit Maldon sea salt) just as much as their down-to-earth cousins.

Four years ago, the British Heart Foundation famously warned that half of all British children were, in effect, drinking five litres of cooking oil a year by virtue of their packet-a-day habit (crisps are a staple in 69% of lunchboxes). More alarmingly, nearly a fifth of British children apparently eat two packets a day. Soaring rates of obesity and Type 2 diabetes were, the foundation warned, the consequences.

The crisp manufacturers complained of unfairness, inaccuracy and exaggeration, and the Savoury Snack Information Bureau – among other things, an active and effective rebuttal service founded to "ensure balanced reporting on the nutritional aspects of savoury snacks in the UK – swung into action. But the industry was stung, and has responded. "It's fair to say awareness has moved on," says Victoria Taylor, a senior dietician at the foundation.

"There have been reductions in salt content and sugar content and saturated fat intake, which is good, although crisps are still fried in fat, so calorie-wise that's not marvellous. There's no more advertising of junk food on children's television, although it's still on programmes lots of children watch. But we need to go further. It's all a question of balance. There are no individual foodstuffs I'd say you should never eat. But if you're eating something once or twice or more a day, then there's no room in your diet for the other foods you need."

In Leicester, they know the numbers off by heart: savoury snacks account for just 1% of saturated fat in the average UK diet, they say. Walkers has spent £20m in research and development since 2003 to make its crisps healthier. Most now contain up to 80% less saturated fat and 55% less salt than they did in 2006. New ranges such as Baked and SunBites contain between 30% and 70% less total fat, and 45% less saturated fat, than standard crisps.

"The point," says general manager Ian Ellington, "is that we have to make a product that consumers want. In the longer term, we're all moving towards consuming less fat and fewer calories, to making healthier choices. If we don't adapt and transform our portfolio, meet those needs while continuing to deliver taste and texture, then there won't be a Walkers brand."

Others are more sceptical. "It's just an idea of pleasure," says Lawrence. "Don't get me wrong, there's nothing wrong with enjoying a pack of crisps every now and again. But the truth is we shouldn't be eating them often; and that's the problem. Because they're selling so little, a packet of air and a few bits of something very cheap, the only way they can make money is by constantly reinventing themselves, and by making sure we eat an awful lot of them."

So, everyone. Are you more Cheese & Onion, or Taw Valley Cheddar & Caramelised Shallots? Personally, I can never decide.

• This article was amended on 1 September 2010. The original said the Britons consume more crisps, crackers and nuts than everyone else in Europe put together. This has been corrected. It also said that larger ("sharing") bags of crisps now account for 29% of the UK crisp market, against 25% five years ago. This has been deleted pending further checks on whether this holds true for the whole market, or specific companies only.

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