Why brain-teasers don't work

Martha Gill's Irrational Animals column.

Question: Beulah died in the Appalachians while Craig died at sea. Everyone was much happier with Craig’s death. Why? Answer: Beulah and Craig were both hurricanes.

Irritating, isn’t it? Brain-teaser questions are all irritating. It’s not that the answers are hard, just that they’re set in a context you’d have to be odd to anticipate. They’re the verbal equivalent of the game where you offer someone a high-five only to slap them in the face, or of dating men in London. Only a hyperalert psychopath could expect to get it right.

But ever since Microsoft decided to use brain-teasers in recruitment interviews back in the 1990s they’ve been spreading like gas in a hermetically sealed kitchen from which you have exactly nine minutes to escape. Tech firms use them; banks use them; Oxbridge has always used them.

They don’t work for hirers, though. They also actively discourage good candidates and have long-term ramifications for a company’s ability to recruit, according to research that came out in October. After putting 360 participants through the mill, Chris Wright of San Francisco State University found that otherwise qualified workers are put off interviews that use brain-teaser questions because they see them as unfair and setting them up for failure.

More than that, Wright found, interviewers don’t know what to do with the answers. The questions are often open-ended with no clear solution, so employers are often impressed with how a retort sounds, rather than what it includes. With open-ended brain-teasers – “Is this a question?” – it’s the smart-arse “Only if this is an answer” that gets points, though I wouldn’t be surprised if the similar “Is your mum a question?” and “Is your face a question?” scored just as high. In Wright’s study, interviewers did a much better job of working out a participant’s skill level after hearing answers to conventional rather than puzzle problems.

In his book Thinking, Fast and Slow the psychologist Daniel Kahneman lists a few puzzles that it’s hard to get right. Here’s one: a bat and ball cost $1.10. The bat costs $1 more than the ball. How much does the ball cost? The answer most people give is ten cents: “intuitive, appealing, and wrong”. That would make the bat $1.10 ($1 more than the ball) and the total $1.20. The answer is five cents.

Not too difficult to work out, in the end, so why do people get it wrong? Kahneman says that it’s a question of motivation. Some people are simply lazy and some are, by nature, “engaged. More alert, more intellectually active, less willing to be satisfied with superficially attractive  answers, more sceptical about their intuitions.”

But I would go further. Some people are expecting to be asked a brain-teaser question and are trying to impress the questioner, and others are simply trying to end the encounter politely so they can get to the bar. If you’re in the latter category, what the brain-teasers are testing is your sensitivity to context. If you’re sensitive enough, you get the answers wrong. Of course you do. The questioner is indicating left. Why would you ordinarily turn right? It would be a monumental waste of energy to expect the unexpected all the time. Thank goodness most of us don’t.

Infant protégé? Photograph: Getty Images

Martha Gill writes the weekly Irrational Animals column. You can follow her on Twitter here: @Martha_Gill.

This article first appeared in the 05 November 2012 issue of the New Statesman, What if Romney wins?

Getty Images/ Staff
Show Hide image

The answer to the antibiotics crisis might be inside your nose

The medical weapons we have equipped ourselves with are losing their power. But scientists scent an answer. 

They say there’s a hero in everyone. It turns out that actually, it resides within only about ten percent of us. Staphylococcus lugdunensis may be the species of bacteria that we arguably don’t deserve, but it is the one that we need.

Recently, experts have cautioned that we may be on the cusp of a post-antibiotic era. In fact, less than a month ago, the US Centres for Disease Control and Prevention released a report on a woman who died from a "pan-resistant" disease – one that survived the use of all available antibiotics. Back in 1945, the discoverer of penicillin, Alexander Fleming, warned during his Nobel Prize acceptance speech against the misuse of antibiotics. More recently, Britain's Chief Medical Officer Professor Dame Sally Davies has referred to anti-microbial resistance as “the greatest future threat to our civilisation”.

However, hope has appeared in the form of "lugdunin", a compound secreted by a species of bacteria found in a rather unlikely location – the human nose.

Governments and health campaigners alike may be assisted by a discovery by researchers at the University of Tubingen in Germany. According to a study published in Nature, the researchers had been studying Staphylococcus aureus. This is the bacteria which is responsible for so-called "superbug": MRSA. A strain of MRSA bacteria is not particularly virulent, but crucially, it is not susceptible to common antibiotics. This means that MRSA spreads quickly from crowded locations where residents have weaker immune systems, such as hospitals, before becoming endemic in the wider local community. In the UK, MRSA is a factor in hundreds of deaths a year. 

The researchers in question were investigating why S. aureus is not present in the noses of some people. They discovered that another bacteria, S. lugdunensis, was especially effective at wiping out its opposition, even MRSA. The researchers named the compound created and released by the S. lugdunensis "lugdunin".

In the animal testing stage, the researchers observed that the presence of lugdunin was successful in radically reducing and sometimes purging the infection. The researchers subsequently collected nasal swabs from 187 hospital patients, and found S. aureus on roughly a third of the swabs, and S. lugdunensis on up to 10 per cent of them. In accordance with previous results, samples that contained both species saw an 80 per cent decrease of the S. aureus population, in comparison to those without lugdunin.

Most notably, the in vitro (laboratory) testing phase provided evidence that the new discovery is also useful in eliminating other kinds of superbugs, none of which seemed to develop resistance to the new compound. The authors of the study hypothesised that lugdunin had evolved  “for the purpose of bacterial elimination in the human organism, implying that it is optimised for efficacy and tolerance at its physiological site of action". How it works, though, is not fully understood. 

The discovery of lugdunin as a potential new treatment is a breakthrough on its own. But that is not the end of the story. It holds implications for “a new concept of finding antibiotics”, according to Andreas Peschel, one of the bacteriologists behind the discovery.

The development of antibiotics has drastically slowed in recent years. In the last 50 years, only two new classes of this category of medication have been released to the market. This is due to the fact almost all antibiotics in use are derived from soil bacteria. By contrast, the new findings record the first occurrence of a strain of bacteria that exists within human bodies. Some researchers now suggest that the more hostile the environment to bacterial growth, the more likely it may be for novel antibiotics to be found. This could open up a new list of potential areas in which antibiotic research may be carried out.

When it comes to beating MRSA, there is hope that lugdunin will be our next great weapon. Peschel and his fellow collaborators are in talks with various companies about developing a medical treatment that uses lugdunin.

Meanwhile, in September 2016, the United Nations committed itself to opposing the spread of antibiotic resistance. Of the many points to which the UN signatories have agreed, possibly the most significant is their commitment to “encourage innovative ways to develop new antibiotics”. 

The initiative has the scope to achieve a lot, or dissolve into box ticking exercise. The discovery of lugdunin may well be the spark that drives it forward. Nothing to sniff about that. 

Anjuli R. K. Shere is a 2016/17 Wellcome Scholar and science intern at the New Statesman