Your Brain Is Lazy, And You Know It

Jedidiah Becker for — Your Universe Online

As a species, humans generally tend to be lazy. We like low-hanging fruit — and from an evolutionary perspective, why shouldn’t we? In the early history of man, when food was dangerously scarce and the unnecessary expenditure of energy potentially fatal, it paid to be judiciously lazy and cut corners wherever you could afford to.

For years, researchers have known that this innate indolence applies to our intellectual life as well. We tend to opt for easy explanations and shoot off facile answers to challenging questions that we haven’t really thought through. In fact, this habit of mind is so widespread that brain scientists refer to humans as “cognitive misers,” Homo ignavus.

But much like physical exertion, this too makes evolutionary sense. The grey matter in our brains – the stuff responsible for most higher-order cognitive processes – is the biological equivalent of a gas-guzzling Hummer. Though it only makes up about 2 percent of our body weight, it gobbles up an astonishing 20 percent or so of our daily energy intake. When humans made the strategic evolutionary switch to surviving by brains rather than brawn, it came with a hefty price tag. From a survival perspective, thinking is expensive, so it pays to only throw our brains into full throttle when we really need to.

This much has been clear for years. What researchers have struggled to understand, however, is the degree to which we are aware that we are being intellectually lazy and recognize that we have probably made a mistake. For years, many researchers have worked under the assumption that we are blissful fools, entirely unaware that we are offering easy and incorrect answers to complex questions.

Now, however, a French study recently published in the journal Psychonomic Bulletin & Review challenges this assumption and claims that we often know we’re taking the intellectually easy way out and, what’s more, that it makes us a little uneasy.

By tweaking a classic psychological test known as the ‘bat-and-ball’ problem, researcher Wim De Neys and his colleagues at the prestigious French National Center for Scientific Research (CNRS) took a fresh look at the question of cognitive carelessness.

In its most basic form, the ‘bat-and-ball’ problem goes something like this: A bat and ball together cost $1.10. The bat costs $1 more than the ball. How much does the ball cost?

The intuitive answer — that is, the one that pops into your mind before you’ve really thought about it — is probably 10 cents. However, a bit of mind-bending basic algebra brings you to the correct answer, which is 5 cents.

But in order to study how people perceive the accuracy of their own answer, the research team wanted to develop a neutralized version of the question that avoids the relative statement (“The bat costs $1 more”). The reason is that this relative element in the sentence triggers the brain to substitute a complex question for a simpler one. So they devised the following dumbed-down control question to accompany the traditional version: “A magazine and a banana together cost $2.90. The magazine costs $2. How much does the banana cost?” The answer to this more straightforward version of the question is 90 cents.

The researchers asked 248 French university students to answer both versions of the problem. After jotting down their response to each question, they were asked to write down how confident they were with their responses on a standard numerical scale.

While 98 percent of the students answered the banana-magazine version of problem correctly, a scant 21 percent were able to get the trickier bat-and-ball version right. Even more important, however, was that the 79 percent of participants who answered incorrectly to the bat-and-ball question indicated that they were significantly less confident of their answer than they were for the simplified control version.

The researchers say that this is a clear indicator that the students were aware that their quick-and-easy answers were likely incorrect and that they were — at least on some level — not entirely oblivious to the fact that they were taking a dubious short cut. It´s as though the brain sends out a little signal to the subconscious saying, “Careful, I´m about to fudge this one — Hope there´s not too much riding on it.”

For de Neys and his colleagues, this minor observation could potentially offer major insights into understanding our brain´s different modes for problem-solving and how these interact with the conscious mind.

“Although we might be cognitive misers, we are not happy fools who blindly answer erroneous questions without realizing it,” concluded the authors. While we may be hard-wired by evolution to conserve our mental energies by cutting corners — a strategy that may often lead us into error — we are not, it seems, blissfully ignorant of our brain´s lazy little tricks.