Stripping Down Science (27 page)

Ask a financier what decides whether the stock market makes money on any given day and they'll invariably talk about bulls and bears, falling FTSEs, downturned Dows, a nifty Nikkei and possibly the prospect of a double-dip depression. But unfortunate as it is to burst this fiscal bubble, recent research has shown that, rather like Russian female athletes in the 1970s, the performance of the stock market is actually heavily dependent on male hormones.

John Coates and Joe Herbert, two researchers at Cambridge University,
⁹⁶
followed 17 male City traders in London over an eight-day period, logging their daily profits and losses and comparing their financial performances with their testosterone levels, which were measured using saliva samples collected at 11 am and 4 pm each day.

‘We were following a hunch I had when I was working on Wall Street during the dot-com
bubble,' explains Coates. ‘I was struck by the fact that the traders at the time were acting very differently before the bubble and after the bubble. [Before,] they were displaying classic symptoms of mania. They were overconfident. They had racing thoughts, diminished need for sleep and they were carrying themselves in such an odd way I began to suspect there was a chemical involved.'

Sure enough, the results from the London traders showed that on days when their 4 pm financial results showed an above-average return, their morning testosterone levels were 25% higher than on days when they made no returns, or lost money.

The researchers had also predicted that on loss-making days the traders would show higher levels of the body's main stress hormone, cortisol. In fact, the saliva samples showed no such relationship. Instead, there was a strong correlation between cortisol and the degree of unpredictability or volatility seen in the market. The harder the market was to read, the higher a trader's cortisol level, which could, Coates thinks, have long-term impacts on the market.

‘In terms of affecting traders' decisions, what it can do is affect the memories you recall. You
tend to recall bad memories, negative precedents. You tend to see risk where maybe there is none. You become fearful, you feel anxiety. I think that decreases a trader's appetite for risk. While testosterone is causing people to take too much risk, cortisol is causing people to take too little risk in the crash,' says Coates.

So these findings could explain the basis of the boom-and-bust nature of financial markets. When times are good, testosterone levels shoot up and boost confidence, which increases impulsivity and promotes willingness to gamble, inflating financial bubbles. It also provokes the release of the brain's pleasure chemical dopamine, possibly explaining why traders talk about getting a buzz from their jobs. Cortisol, on the other hand, makes traders risk-averse, causing crashes to become entrenched and turning ‘dot com' into ‘dot bomb'. But can this new knowledge help to dig the world out of the present downturn?

‘Cortisol is a hormone that responds not just to loss or injury (loss being in this case money); it also responds more powerfully to situations of novelty, uncertainty and uncontrollability. Within banks, I think it's extremely important to create an environment that minimises the trader's
feeling of uncontrollability. Managers think they have to be proactive to show that they're doing something to improve the situation. But usually what they're doing is threatening to fire people. That's exactly the wrong thing you should be doing.'

One also has to wonder what would happen if there were a few more female stockbrokers. Having less than 10% of the testosterone of a male, it's entirely possible that women might not succumb to the same hormone-fuelled episodes of financial overexuberance …

If girls are made of sugar and spice and all things nice, then why are their hands covered in
E. coli
? The view amongst the masses (or maybe that should be the great unwashed?) is that women are generally better-scrubbed than men. But this turns out to be a microbiological myth, at least in many instances. The grimy truth, revealed by a study of commuters' hands spanning the length and breadth of Britain, is that up to 30% of women in some parts of the country have hands covered in faecal bugs!

Called the ‘Dirty Hands Study', this national quest in pursuit of hand-borne faecal filth was set up by London School of Hygiene and Tropical Medicine researcher Val Curtis and her colleagues
⁹⁷
in recognition of the launch of Global Handwashing Day in November 2008. Between August and September of the same year, they sent
out students armed with swabs to prowl amongst lines of queuing commuters at the transport terminals of five major cities: London, Cardiff, Birmingham, Liverpool and Newcastle. In total, over 400 commuters consented to have their hands swabbed down to see what was lurking on the skin. The samples were sent to the microbiology laboratory for culture and identification. Nearly 30% of them tested positive for the presence of faecal bacteria, including
Enterococcus
and
E. coli
, two common gut bugs. Yuck!

So who shouldn't you shake hands with while en route? In general, bus passengers and people living in the north of the country emerged as the worst culprits. On average, one in every three bus users was ferrying faecal organisms on their fingers, compared with the approximately one-quarter of rail commuters who were found to be carrying more than just their luggage.

There was also an association between job description and the risk of being found to be foul-handed. Manual workers were amongst the least likely to test positive, growing bugs from their swabs only about 10% of the time, and professionals came up red-handed in about a quarter of cases. But the real typhoid Marys
– with a whopping 40% contamination rate – turned out to be those describing themselves as administrators. Administering what exactly, you may well ask?!

The most interesting results emerged, though, when the researchers divided up the results by sex. In London, 13% of people in total were positive, with women coming up trumps 20% of the time, compared with just 6% of men. But this trend reversed the further north the researchers looked. In Birmingham, mid-way up the country, the rates were about equal between men and women, with about 25% of people testing positive; but in Newcastle, that number was close to a gross 50% of all travellers. Of the women, 30% tested positive along with a massive 60% of the men. The reasons for these trends aren't altogether clear. One possibility is that further north, commuters may have further to travel and therefore the chances of picking up bugs could rise in proportion to the length of the journey.

The bugs that were detected in the study – commonly
Enterococci
– aren't themselves serious pathogens, at least in a healthy person, but they do serve as a useful marker of faecal contamination and general poor hygiene. Other agents that
spread similarly – like the dreaded norovirus, which causes projectile vomiting and diarrhoea – could easily be there too (the researchers didn't look) and are much nastier. This is probably the reason why so many people – in the UK, an estimated one in five – experience at least one case of diarrhoea or vomiting each year.

According to Val Curtis, ‘We were absolutely flabbergasted so many people had faecal bugs on their hands. If these people had been suffering from a diarrhoeal disease, the potential for it to be passed round would be greatly increased by their failure to wash their hands after going to the toilet …'

So were all the people who tested positive practitioners of poor hygiene? Probably not. In all likelihood, many of them had picked up the bugs from surfaces they had touched in the course of making their journeys. All it takes is one person who doesn't wash their hands to touch a surface and whatever's on their skin can then end up on the hands of anyone else who touches that same surface later.

This is why the rules regarding doors on public toilets should be rewritten to ensure that they can be pushed open with feet or a shoulder on the way
out, so there's only a need to pull them open with a handle on the way in. People are much more likely to be contaminated when they leave than when they come in, so this strategy would avoid the one person who doesn't wash their hands from upsetting the applecarts, and the stomachs, of the more conscientious handwashers among us.

FACT BOX

Another reason why your hands might land you in it

Apart from criminal levels of contamination on the hands of British commuters, scientists have found that the unique collections of bacteria we leave behind on the things we touch could also be used to place us at the scenes of crimes in future.

Scientists have known for a long time that the human body plays host to a massive community of microbes. In fact, some have gone as far as to describe us as passengers
in our own bodies, because the number of bacterial cells living on us and in us outnumber our own cells by at least 50 to 1.

Most of these bugs are so-called ‘good bacteria'. In the intestines, they lend their genetic know-how to assist in the breakdown of what would otherwise be indigestible foodstuffs. They also synthesise certain vitamins and micronutrients, and they protect the host from pathogenic microbes by preventing bacterial and fungal ‘nasties' from gaining a nutritional toehold. On the skin, they do similar jobs.

But in recent years, scientists have discovered, largely thanks to the power of modern genetic sequencing techniques, that the diverse community of bacteria that we all carry is as unique to each of us as our own fingerprints. In essence, we have a unique and stable ‘bacterial fingerprint' (which can also include anything we pick up transiently from bus passengers and people from the north of England). So even after a handwash with soap, within a few hours the same spectrum
of microbes, unique to each of us, is back in place on the skin.

Now researchers have shown that this bacterial badge can be used forensically. University of Boulder, Colorado, scientist Noah Fierer and his colleagues
⁹⁸
took swabs from computer mice and keyboards and were able to produce a genetic profile of the bacteria present and then pick out correctly – from more than 250 possible pairs of hands – the correct computer owners.

Although they point out that further investigation and validation of the technique will be necessary to establish its forensic credentials, the researchers think that it could be a powerful add-on to existing methods, like human DNA fingerprinting. ‘This approach might represent a valuable alternative to more standard techniques,' they point out. ‘Given the abundance of bacterial cells on the skin surface and on shed epidermal cells, it may be easier to recover bacterial DNA than human
DNA from touched surfaces.'

So, would-be criminals are advised to take a shower immediately before breaking and entering!

LUNCH BOX

Food for thought

Apart from gut microbial fingerprints, scientists have also shocked the world recently with the discovery that one common strain of human gut bug appears to have borrowed a set of genes from a marine microbial cousin – to help it to digest its host's diet of sushi!

Gurvan Michel, a researcher at the University of Victoria in British Columbia,
⁹⁹
had been studying a sea-dwelling bacterium called
Zobellia galactanivorans
, which is a member of the
Bacteroides
family of bacteria.
He found that these bugs carry genes that enable them to make a newly identified class of enzymes called porphyranases. These can break down sugar-based polymers known as porphyrans that are present in large amounts in certain types of seaweeds, including the ones used to wrap up sushi.