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?

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An antibiotic-resistant superbug is silently spreading through UK hospitals

There have already been outbreaks in Manchester, London, Edinburgh, and Birmingham, but deaths are not centrally recorded. 

Lying in a hospital bed, four months pregnant, Emily Morris felt only terror. She had caught a urinary tract infection and it was resistant to common antibiotics. Doctors needed to treat it as it could harm the baby, but the only drugs that could work hadn’t been tested on pregnant women before; the risks were unknown. Overwhelmed, Emily and her husband were asked to make a decision. A few hours later, gripping each other’s arms, they decided she should be given the drugs.

In Emily’s case, the medicine worked and her son Emerson (pictured below with Emily) was born healthy. But rising antibiotic resistance means people are now suffering infections for which there is no cure. Doctors have long warned that decades of reliance on these drugs will lead to a "post-antibiotic era"– a return to time where a scratch could kill and common operations are too risky.

It sounds like hyperbole – but this is already a reality in the UK. In the last four years 25 patients have suffered infections immune to all the antibiotics Public Health England tests for in its central lab, the Bureau of Investigative Journalism has discovered.

While these cases are rare, reports of a highly resistant superbug are rising, and infection control doctors are worried. Carbapenem resistant enterobacteriaceae (CRE) are not only difficult to pronounce, but deadly. These are bugs that live in the human gut but can cause an infection if they get into the wrong place, like the urinary tract or a wound. They have evolved to become immune to most classes of antibiotics – so if someone does become infected, there are only a few drugs that will still work. If CRE bacteria get into the bloodstream, studies show between 40 per cent and 50 per cent of people die.

These bugs are causing huge problems in India, certain parts of Asia, the Middle East and some countries in southern Europe. Until recently, most infections were seen in people who had travelled abroad, had family members who had, or had been in a foreign hospital. The boom in cheap cosmetic surgery in India was blamed for a spate of infections in Britain.

Now, doctors are finding people who have never boarded a plane are carrying the bug. There have already been outbreaks in Manchester, London, Liverpool, Leeds, Edinburgh, Birmingham, Nottingham, Belfast, Dublin and Limerick among other areas. Patients found with CRE have to be treated in side rooms in hospital so the bacteria does not spread and harm other vulnerable patients. But in many of Britain’s Victorian-built hospitals, single rooms are in sparse supply. Deaths from CRE aren’t centrally recorded by the government - but it is thought hundreds have already died. 

Across the country, doctors are being forced to reach for older, more toxic drugs to treat these infections. The amount of colistin – called the "last hope" antibiotic as it is one of few options still effective against CRE infections - rose dramatically in English hospitals between 2014 and 2015, the Bureau has revealed. Colistin was taken off the shelves soon after it was introduced, as it can harm the kidneys and nervous system in high doses, but was reintroduced when infections became immune to standard treatment. The more we use colistin the more bacteria develop resistance to it. It’s only a matter of time before it stops working too, leaving doctors’ arsenal near-empty when it comes to the most dangerous superbug infections.

Due to a kidney problem, Emily Morris suffers repeat urinary tract infections and has to be hospitalised most months. Her son Emerson comes to visit her, understanding his mummy is ill. If she catches a superbug infection, she can still be given intravenous antibiotics to stem it. But she worries about her son. By the time he is an adult, if he gets ill, there may be no drugs left that work.

Madlen Davies is a health and science reporter for the Bureau of Investigative Journalism