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?

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.