When it comes to discussing suicide bombers, the controversial topic of religion is never far behind. Scholars and pundits have proposed several theories to explain why people would sacrifice their lives to take those of others, and conjectures about religious views seem easy to defend. After all, anthropologist Scott Atran estimated that since 2000, 70% of suicide attacks have been carried out by religious groups, and Islamic ones in particular.

But for all the speculation, very few people have examined the supposed link between religion and suicide attacks with an objective scientific eye. Enter Jeremy Ginges from the New School for Social Research in New York. He has used four related studies to show that there is indeed a link between religion and support for suicide attacks, but it’s a complicated one.

Ginges studied a wide variety of religious people from various cultures and faiths – from Palestinian Muslims to Israeli Jews, and from British Protestants to Indian Hindus. Across the board, Ginges found that a person’s stance on martyrdom had little to do with their religious devotion or to any particular religious belief. Instead, it was the collective side of religion that affected their stance – those who frequently took part in religious rituals and services, were most likely to support martyrdom.

Various commentators have suggested that religious devotion makes it easier for people to buy into the ethos of suicide attacks because some religious beliefs denigrate those of other faiths, promise rewards in the afterlife or glorify the notion of martyrdom. According to Ginges, the advocates of this idea, Richard Dawkins among them, tend to bias their attention towards the more violent aspects of religious traditions or texts, in a fairly simplistic way.

An alternative idea says that the social side of religion is the more powerful influence. During religious rituals such as church or mosque services, large groups of people move or speak as one, invoking a powerful sense of shared identity. By strengthening bonds within a group, these rituals can augment a person’s loyalty to that community, often to the exclusion of those outside it. Suicide attacks, which sacrifice a person’s life for the sake of the collective cause, could be viewed as the extreme dark side of this cliquey behaviour.

Ginges, together with Ian Hansen and Ara Norenzayan, carried out four studies to distinguish between these two theories and they’ve consistently found support for the latter, across a variety of religions.

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It’s a scene straight out of a horror film – you look around and see dead bodies everywhere. They haven’t just been killed either, they’ve been hollowed out from the inside-out leaving behind grotesque mummified shells. What would you do if you were confronted with such a macabre scene? Flee? Well, if you were an aphid, you’d probably just feel relieved and go about your business. Aphids, it seems, find security among the corpses of their peers.

Aphids, like almost all insects, are the targets of parasitic wasps that implant eggs inside their bodies. On hatching, the wasp grubs use the aphid as a living larder and eat their way out, leaving behind a mummified aphid-shaped husk.

These husks ought to be (quite literally) a dead give-away that parasites are afoot, valuable intel for any animal. But far from treating these bodies as a sign of danger, aphids actually see them as a reason to stick around. As Fievet says, “In human history, mummies had long been known to protect the dead; our study shows that in nature, mummies can also protect the living.”

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As of yesterday, I have written 400 proper articles for this blog.

Woo, and I might add, hoo.

That’s excluding random announcements, navel-gazing, chatter or the odd journalistic take-down. Four hundred summaries, each covering one or more new pieces of research. Each one probably represents about 2.5 hours of work, and it’s taken about 2.5 years to accumulate all of them. But it’s been worth it, for me certainly and I hope for people reading too.

If you’re new to Not Exactly Rocket Science, you can find the entire back catalogue in “The Full Works“.  Or if you want a taster, have a look at my top picks from 2008, or the recent Darwin celebration series.

The other thing I realised, was that it took 18 months to write the first 200 posts and just 12 to write the next 200. So I’m speeding up. See you soon for the 500th anniversary post.

Babies can say volume without saying a single word. They can wave good-bye, point at things to indicate an interest or shake their heads to mean “No”. These gestures may be very simple, but they are a sign of things to come. Year-old toddlers who use more gestures tend to have more expansive vocabularies several years later. And this link between early gesturing and future linguistic ability may partially explain by children from poorer families tend to have smaller vocabularies than those from richer ones.

Vocabulary size tallies strongly with a child’s academic success, so it’s striking that the lexical gap between rich and poor appears when children are still toddlers and can continue throughout their school life. What is it about a family’s socioeconomic status that so strongly affects their child’s linguistic fate at such an early age?

Obviously, spoken words are a factor. Affluent parents tend to spend more time talking to their kids and use more complicated sentences with a wider range of words. But Meredith Rowe and Susan Goldin-Meadow from the University of Chicago found that actions count too.

Children gesture before they learn to speak and previous studies have shown that even among children with similar spoken skills, those who gesture more frequently during early life tend to know more words later on. Rowe and Goldin-Meadow have shown that differences in gesturing can partly explain the social gradient in vocabulary size.

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The mainstream media are just queuing up to fail in their reporting of the propranolol story from a couple of days ago. To reiterate:

Propranolol is commonly used to treat high blood pressure and prevent migraines in children. But Merel Kindt and colleagues from the University of Amsterdam have found that it can do much more. By giving it to people before they recalled a scary memory about a spider, they could erase the fearful response it triggered.

The critical thing about the study is that the entire memory hadn’t been erased in a typical sci-fi way. Kindt had trained the volunteers to be fearful of spidery images by pairing them with electric shocks. Even after they’d been given propranolol, they still expected to receive a shock when they saw a picture of a spider – they just weren’t afraid of the prospect. The drug hadn’t so much erased their memories, as dulled their emotional sting. It’s more like removing all the formatting from a Word document than deleting the entire file.

The drug is not a “memory-wiping pill” (Guardian). It cannot “erase bad/painful memories” (Sun/ Fox News/ Metro/ Daily Mail) and it won’t give you a “spotless mind” (Scotsman). Perhaps it’s unsurprising given that massive wire agencies said similar things. The Press Association led with claims that the drug can “erase fearful memories“. Reuters at least said more cautiously that it was a “step towards erasing bad memories“.

To quote the person who actually did the research (and thanks Merel for chiming in on the earlier post): 

“There was no memory erasure, just elimination of the fearful response.”

The problem with all of this, of course, is that people have straw-manned the research and are falling over themselves to publish trite editorials that (a) are irrelevant to the actual study and (b) serve to stoke public outrage over an ethical dilemma of their own concoction.

There are exceptions. The Boston Globe got it right and has a brilliant bit at the end that lays out in four simple sentences the bottom line, cautions, what’s next, and where the research was published. It has however accompanied the article with an incongruous photo of a koala, presumably some sort of mix-up with the Australian bushfire story.

The mental health charity MIND released a long and well-considered statement, which showed that they had actually read the paper and understood the science. The charity’s CEO, Paul Farmer, said:

“This is fascinating research that could transform the treatment for phobias and post traumatic stress disorder. Around 10 million people in the UK have a phobia and about 3.5% of the population will be affected by post traumatic stress disorder at some point yet our understanding of how to treat these conditions is still limited. While we welcome any advancement in this field we should also exercise caution before heralding this as a miracle cure.

“Eradicating emotional responses is clearly an area we would need to be very careful about. It could affect people’s ability to respond to dangerous situations in the future and could even take away people’s positive memories. We would not want to see an ‘accelerated Alzheimer’s’ approach.

“We still have limited research on how to treat complex mental health problems, with the focus often on pharmacological solutions. Drugs are a somewhat sledgehammer approach and can have unintended consequences. We know from other psychiatric drugs, for example antipsychotics and antidepressants, that individuals react in hugely varied ways to treatments and are often vulnerable to unpleasant side effects.

“We would need to see much more research into the risks and benefits into this treatment before it becomes a reality.”

All of that was culled by the BBC into the following:

But British experts questioned the ethics of tampering with the mind.

Paul Farmer, chief executive of mental health charity Mind, said he was concerned about the “fundamentally pharmacological” approach to people with problems such as phobias and anxiety.

He said the procedure might also alter good memories and warned against an “accelerated Alzheimer’s” approach.

Do you think it carries the same meaning or sense?

The wiping of unwanted memories is a common staple of science-fiction and if you believe this weekend’s headlines, you might think that the prospect has just become a reality. The Press Association said that a “drug helps erase fearful memories“, while the ever-hyperbolic Daily Mail talked about a “pill to erase bad memories“. The comparisons to The Eternal Sunshine of the Spotless Mind were inevitable, but the actual study, while fascinating and important, isn’t quite the mind-wiper these headlines might have you believe.

The drug in question is propranolol, commonly used to treat high blood pressure and prevent migraines in children. But Merel Kindt and colleagues from the University of Amsterdam have found that it can do much more. By giving it to people before they recalled a scary memory about a spider, they could erase the fearful response it triggered.

The critical thing about the study is that the entire memory hadn’t been erased in a typical sci-fi way. Kindt had trained the volunteers to be fearful of spidery images by pairing them with electric shocks. Even after they’d been given propranolol, they still expected to receive a shock when they saw a picture of a spider – they just weren’t afraid of the prospect. The drug hadn’t so much erased their memories, as dulled their emotional sting. It’s more like removing all the formatting from a Word document than deleting the entire file. Congatulations to Forbes and Science News who actually got it right.

Kindt’s work hinges on the fact that memories of past fears aren’t as fixed as previously thought. When they are brought back to mind, proteins at the synapses – the junctions between two nerve cells – are broken down and have to be created from scratch. This process is called “reconsolidation” and scientists believe that it helps to incorporate new information into existing memories. The upshot is that when we recall old memories, they have to be rebuilt on some level, which creates an opportunity for changing them.

A few years ago, two American scientists managed to use propranolol to banish fearful responses in rats. They injected the animals in their amygdalae, a part of their brains involved in processing emotional memories. The drug didn’t stop a fearful memory from forming in the first place, but it did impair the memory when the rats tried to retrieve it. Now, Kindt has shown that the chemical has the same effect in humans.

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A child in the womb is not just some hapless creature waiting to be born into a world of experience. It is preparing. Through its mother, it senses the conditions of the world outside and its body plans its growth accordingly.

There is strong evidence that people who are under-nourished as embryos grow up to have higher risks of heart disease and other chronic illnesses. For example, people born to women during the Dutch Famine of 1945 had higher risks of coronary heart disease as adults.

We might nod our heads at this as if it were expected news, but it’s actually quite a strange result. After all, during the early stages of pregnancy, the embryo is actually relatively undemanding. Any embryos that get off to an early slow start can easily catch up during the foetal stage, and they can certainly do it after birth. But Jane Cleal and colleagues from the University of Southampton have found, from studying sheep, that catching up may actually be the problem.

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In the summer of 2007, thirty-four travellers left home with backpacks in tow to see the world. But these weren’t human students, out to get drunk and pretentious find themselves in foreign lands – they were small songbirds, migrating to tropical climates for the winter.

Their backpacks were light-measuring devices called “geolocators”, each about the size of a small coin. By measuring rising and falling light levels, these miniature contraptions revealed the timings of sunrise and sunset wherever the birds happened to be flying. Those, in turn, revealed where they were in the world, and allowed Bridget Stutchbury from York University, Toronto to achieve a world-first – track the entire voyage of a migrating songbird, from the start of the outbound trip to the end of the return journey.

The recordings show that tiny wood thrushes and purple martins are far more capable fliers than anyone had thought. They can cover 500 kilometres in a day, flying more than three times as fast as previously expected. Previous studies had credited these tiny fliers with top migration speeds of just 150 km/day. But these had major flaws.

Songbirds are so small that they can’t be tracked by satellites, making their annual migrations difficult to track. Until now, what we knew about their journeys came from brief glimpses on radar or studies done at pit-stops along the way. One incredible study managed to track thrushes during a short part of their travels by injecting them with mildly radioactive isotopes and following them in a plane. All of these studies have provided mere glimpses of the overall migration, like piecing together a movie from still shots and trailer clips. Stutchbury’s team from the University of York, Toronto have managed to record the entire film.

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This is the eighth of eight posts on evolutionary research to celebrate Darwin’s bicentennial.

In Virginia, USA, sits a facility called the American Type Culture Collection. Within its four walls lie hundreds of freezers containing a variety of frozen biological samples and among these, are 99 strains of the common cold. These 99 samples represent all the known strains of the human rhinoviruses that cause colds. And all of their genomes have just been laid bare.

Ann Palmenberg from the University of Wisconsin and David Spiro from the J. Craig Venter Institute have cracked the genomes of all 99 strains, and used them to build a family tree that shows the relationships between them. Already, it has started to plug the holes in our understanding of this most common of infections. It reveals how different strains are related and how new strains evolve. It tells us which features are shared by all strains and which are the more unique traits that making rhinoviruses such slippery targets.

This extra knowledge may go some way to remedying the slightly baffling situation we find ourselves in, where all the vaunted progress of modern medicine has failed to produce a single approved treatment for an infection that most of us get at least twice a year.

The 99 historical strains of human rhinovirus fall into two separate species – HRV-A and HRV-B. More recently, a possible third species – HRV-C – has been identified in patients hospitalised with severe, flu-like illnesses. To build their family tree, Palmenberg and Spiro analysed the complete genomes of all 99 strains from the Virginia facility, seven samples of HRV-C, and 10 fresh samples collected from patients just a few years ago.

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This is the seventh of eight posts on evolutionary research to celebrate Darwin’s bicentennial. It combines many of my favourite topics – symbiosis, horizontal gene transfer, parasitic wasps and viruses.

Parasitic wasps make a living by snatching the bodies of other insects and using them as living incubators for their grubs. Some species target caterpillars, and subdue them with a biological weapon. They inject the victim with “virus-like particles” called polydnaviruses (PDVs), which weaken its immune system and leave the wasp grub to develop unopposed. Without the infection, the wasp egg would be surrounded by blood cells and killed.

The wasps’ partners in body-snatching are very different to all other viruses. Once they have infected other cells, they never use the opportunity to make more copies of themselves. They actually can’t. To complete their life cycles, viruses need to package their genetic material within a coat made of proteins. In most cases, the instructions for building these coats are encoded within the virus’s genome, but polydnaviruses lack these key instructions entirely. Without them, the virus is stuck within whatever cell it infects.

It’s such a weird set-up that some scientists have questioned whether the polydnaviruses actually count as viruses at all or whether they are “genetic secretions” from the wasps themselves. Where on earth are those missing coat genes?

Annie Bezier form Francois Rabelais University has found the answer and it’s an astonishing one. The viruses’ coat genes haven’t disappeared – they’ve just been relocated to the genomes of their wasp hosts.

In this way, the wasps and the viruses have formed an unbreakable alliance, where neither can survive without the other’s help. Without the virus, the next generation of wasps would be overwhelmed by the defences of their caterpillar larders. Without the wasp, the virus would never be able to reproduce. Some viruses may be able to live happily alongside their host with little ill effect; others may even be beneficial in some way. But this is the first example of a virus co-evolving with its host in a compulsory binding pact.

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