SATOSHI KANAZAWA is Reader in Management at the London School of Economics and Political Science, and Honorary Research Fellow in the Department of Psychology at Birkbeck College, University of London. He has written over 80 articles across the fields of psychology, sociology, political science, economics, anthropology and biology. One such was his widely reported article “Why Liberals and Atheists Are More Intelligent” (2010). His latest book is called “The Intelligence Paradox: Why the Intelligent Choice Isn't Always the Smart One” (2012).

What, if any, evolutionary advantage does intelligence give us?

Actually, less intelligent people are better at doing most things. In the ancestral environment general intelligence was helpful only for solving a handful of evolutionarily novel problems.

Suggested reading: “The Bell Curve: Intelligence and Class Structure in American Life” by Herrnstein, Richard J. and Charles Murray (1994)

You mean our ancestors did not really have to reason?

Evolution equipped humans with solutions for a whole range of problems of survival and reproduction. All they had to do was to behave in the ways in which evolution had designed them to behave—eat food that tastes good, have sex with the most attractive mates. However, for a few evolutionarily novel problems, evolution equipped us with general intelligence so that our ancestors could reason in order to solve them.  These evolutionarily novel problems were few and far between. Basically, dealing with any type of major natural disaster that is very infrequent in occurrence would require general intelligence.

Suggested reading: “Evolutionary Psychology and Intelligence Research” by Satoshi Kanazawa, in American Psychologist;  65: 279-289 (2010)

Why do we consider intelligence to be so important in modern life?

General intelligence is very important in modern life because our environment is almost entirely evolutionarily novel. Most of the problems that we have to solve today—how to excel in school, how to find jobs, how to do virtually everything on a computer—are evolutionarily novel. So intelligent people do well in almost every sphere of modern life, except for the most important things, like how to find a mate, how to raise a child, how to make friends. Intelligence does not confer any advantage for solving all the evolutionarily familiar problems that our ancestors encountered. More intelligent people do not have any advantage in finding mates and often have disadvantages.

Suggested reading: Gottfredson, Linda S. (Editor.) 1997. “Special Issue on Intelligence and Social Policy” by Linda S. Gottfredson in Intelligence; Volume 24, Issue 1 (January-February 1997).

Why would being a good problem solver mean you were less good at the ordinary more instinctive behaviour?

General intelligence evolved to solve evolutionarily novel problems, so intelligent people are more likely to acquire and espouse evolutionarily novel preferences and values. They are more likely to recognise and develop tastes for things that our ancestors did not have 100,000 years ago. For example, more intelligent people are more likely to be left-wing liberals because our ancestors were “conservative” by the contemporary American definition—they only cared about the well-being of their friends and family. They are more likely to be atheist because the preferred theory in evolutionary psychology is that humans are designed to believe in God.

Really?

Humans appear to be designed to be paranoid; they are designed to see intentional agents behind natural phenomena. This is because making the mistake of thinking that a natural event has an intentional agent behind it is less potentially costly than being oblivious and thinking that an intentional event, like someone trying to kill you, has a coincidental cause. The paranoid outlive the oblivious. Belief in God may be a consequence of this tendency. Intelligent people are more likely to be nocturnal because humans are designed to wake up when the sun comes up and go to sleep when the sun goes down. They are more likely to be homosexual, because humans are evolutionarily designed to reproduce heterosexually. They are more likely to enjoy instrumental music because music in its evolutionary origin was vocal, and they are more likely to consume alcohol, cigarettes and drugs because all of these substances are evolutionarily novel. 

Surely intoxication is a way of not thinking? And isn't drug and alcohol addiction worse among the disadvantaged?

Some people suggest that more intelligent people think too much and therefore need alcohol to stop thinking, but that's not my argument. My point is that the human consumption of alcohol, tobacco and psychoactive drugs is a relatively new phenomenon. Both the American and British population data (nationally representative samples of Americans and Brits) show that more intelligent people consume more alcohol more frequently.

So intelligent people do not behave better than less intelligent people?

No, sometimes they do stupid things. What intelligent people prefer is not good or bad, right or wrong, but it is always evolutionarily novel.  More intelligent boys (but not more intelligent girls) are more likely to grow up to value sexual exclusivity. This is because humans are naturally polygynous. Sexual exclusivity is evolutionarily novel for men but not for women, so more intelligent men are more likely to value sexual exclusivity than less intelligent men. There is also some evidence that intelligent people are more likely to be vegetarians, because humans are evolutionarily designed to be omnivorous. 

Criminals on average have lower intelligence than law-abiding citizens. Firstly, most behaviours designated as crimes are just natural means of competition that men have engaged in throughout evolutionary history. Secondly, institutions and technologies that control criminal behaviour today—CCTV cameras, police, court, prison—are all evolutionarily novel, so less intelligent men are less likely truly to comprehend such entities.

Suggested reading: “The Singing Neanderthals: The Origins of Music, Language, Mind and Body”by Steven Mithen (2005); and “Why Night Owls Are More Intelligent” by Satoshi Kanazawa and Kaja Perina in Personality and Individual Difference; 47:  685-690 (2008)

You say less intelligent people are good at the important things. What are they?

Would you rather be a good brain surgeon or a good parent? Would you rather be a good corporate executive or a good friend? More intelligent people don't always make good parents or friends. Intelligent women make the worst kind of parents, simply because they are less likely to become parents in the first place. There is also some evidence that children of more intelligent women are more likely to suffer from health and behavioural problems, probably due to the fact that they tend to have children later.

Why?

Because reproductive success is the ultimate goal of all living organisms, so intelligent women are more likely to go against such evolutionary design. My theory would also predict that intelligent men should be less likely to become parents, but data do not confirm that. Some suggest that women prefer to have children with more intelligent men, but the data contradict this too. Men's income or education has no effect on their likelihood of becoming parents. Intelligence doesn't allow us to do better what we are designed by evolution to do. Saint Exupery writes; “Voici mon secret.  Il est très simple: on ne voit bien qu'avec le cœur.  L'essential est invisible pour les yeux.”

Suggested reading: “Le Petit Prince” by Antoine de Saint-Exupéry (1943)