Why Are Humans Smarter Than We Need To Be?

Q: Why did mankind develop such high intelligence? I mean, it’s not as if less intelligent creatures are having trouble sustaining their respective species. So why do we have this brilliant feature to begin with? – Yousaf Bajwa

how does evolution influence intelligence?We’re smarter than we need to be because we have big brains, Yousaf. We have big brains because, well, umm… I don’t know for sure.

There have been various theories, some more persuasive than others. It was once believed, for example, that our big brains served as radiators. Long ago, someone apparently noticed that blood courses through the head in large volume, making the noggin an ideal mechanism for shedding excess heat. Of course, this is like saying that the function of IBM’s Deep Blue is to eliminate excess electricity.

A slightly better theory holds that the brain evolved as a courtship mechanism, like the horns of bighorn sheep or the tail feathers of a peacock. That’s closer, but still no cigar. A brain that evolved merely for courtship would give us a species of Machiavellian Lotharios who lacked practical skills like hunting or building things. In other words, the world would be filled with senators and other high-level politicians. Still, we can’t discount sex in evolution, so let’s come back to that topic.

The most persuasive theory, in my opinion, involves eating. We have always been hunters, and like any species of hunters, we need to fill an ecological niche. Ours happens to be the cognitive, problem-solving niche. Humans cannot run fast, fly, or maul things with giant claws, but we excel at cracking the defenses of other species. We are so skilled at problem-solving, in fact, that there is hardly a creature on earth we cannot capture (especially the tasty ones).

In How the Mind Works, Steven Pinker lays out the theory in typical lucid fashion. He explains that the cognitive skills involved in the daily life of ancient hunter-gatherers are the skills we carry today. Mechanisms like speech, spatial reasoning, memory, and creativity allowed humans to thrive in any environment and conquer any quarry. According to Pinker,

“All foraging peoples manufacture cutters, pounders, containers, cordage, nets, baskets, levers, and spears and other weapons. They use fire, shelters, and medicinal drugs. Their engineering is often ingenious, exploiting poisons, smokeouts, glue traps, gill nets, bated lines, snares, corrals, weirs, camouflaged pits and clifftops, blowguns, bows and arrows, and kites trailing sticky fishing lines made out of spider silk.

“The reward is an ability to crack the safes of many other living things: burrowing animals, plants’ underground storage organs, nuts, seeds, bone marrow, tough-skinned animals and plants, birds, fish, shellfish, turtles, poisonous plants (detoxified by peeling, cooking, soaking, parboiling, fermenting, leaching, and other tricks of the kitchen magician), quick animals (which can be ambushed), and large animals (which cooperating groups can drive, exhaust, surround, and dispatch with weapons).”

As to the question of why humans alone carry these cognitive armaments, Pinker explains that three factors gave early primates the mental edge.

First, primates are visual animals, which gave our ancestors the ability to understand three-dimensional space and led to specialized forms of reasoning. Second, we are social animals. That led us to value information, and it created complex social challenges requiring abstract solutions. Third, primates have hands, which Pinker describes as “levers of influence on the world that make intelligence worth having.”


Sex and the Single Prehistoric Girl

Evolutionary psychologists make a compelling case that competition against other species was the driving force in our cognitive development. To a lesser degree, but still important, our cognitive evolution was also shaped by competition against each other, as we battled and jockeyed for mates.

To start with the basics, women have finite resources to devote to reproduction – it takes a lot of energy to survive pregnancy and rear a child through the first few years of life – while men have practically unlimited reproductive potential. This has forced women to become the choosier of the genders. It is no surprise that women have come to value things like social status and physical attractiveness, since they have become indicators of ability to be a good long-term provider (in the case of social status) and good genes (in the case of physical attractiveness).

Interestingly, women aren’t always motivated to pursue the same traits in males. One minute, a woman may be more attracted to indicators of good genes; the next minute, she may favor indicators of good fathering ability. Why? Women have learned that good genes and good fathering don’t always exist in the same man, and so the qualities that she finds attractive can fluctuate with her menstrual cycle. At the most fertile phase of the cycle, a woman’s attraction toward indicators of good genes tends to increase (Geary et al., 2004; Gangestad et al. 2004).

This is where intelligence comes in – sort of. You wouldn’t know it by watching Maury Povich, but females of our species long ago decided that smart is sexy. According to at least one study, women are adept at quickly detecting intelligence in men, perhaps by subconsciously monitoring traits like creativity and verbal fluency (Prokosch et al., 2009). But what, exactly, does intelligence signify – that a man has good genes, or that he will be a good provider? If Prokosch and company are correct, the answer is both:

“…(1) intelligence indicates the individual’s potential provisioning abilities, consistent with the ‘good provider’ paradigm in human mate choice research; and (2) intelligence is a reliable cue of the individual’s ‘good genes’ in that it provides an accurate assessment of the individual’s overall mutation load and fitness.”

Traits like good looks and status may be of fluctuating interest to women, but all things being equal, intelligent men are always more attractive to women than dunces. All of that is a long-winded way of saying that smart men have historically enjoyed a better shot at coupling with desirable women who are likely to provide viable offspring. That, in turn, means that traits of intelligence have had an advantage in being carried forward to the next generation. And despite our evolved sensibilities about mate choice, research suggests that we are still influenced by these ancient rules (Todd, et al., 2007).

It’s all so heartless and calculating, isn’t it? Where’s the romance?

Actually, I think that this ruthless process of evolution has given us something entirely adorable: the intelligence to write sappy poetry and conquer the universe for love. I’ve long said that men would be lost without women, and that everything men do is to earn their favor. In true geek fashion, I will ground my closing argument in science fiction. In the movie Star Trek: First Contact, Professor Zephram Chochrane explained why he invented warp drive:

“I didn’t build this ship to usher in a new era for humanity. You think I want to go to the stars? I don’t even like to fly! I built this ship so I could retire to some tropical island filled with naked women.”

Crass, but instructive. There is no immediate survival value to things like space exploration. In fact, it’s downright dangerous. But we do it anyway because women have helped us become a species of irrepressible problem-solvers. I take it as evidence that the wisdom of the fairer sex knows no bounds. Happy Valentine’s Day.


Gangestad, S.W., Simpson, J.A., Cousins, A.J., & Garver-Apgar, C.E. (2004). Women’s preferences for male behavioral displays change across the menstrual cycle. American Psychological Society, 15(3), 203-207.

Geary, D.C., Vigil, J., & Byrd-Crave, J. (2004). Evolution of human mate choice. The Journal of Sex Research, 41(1), 27-42.

Haselton, M.G. & Miller, G.F. (2006). Women’s fertility across the cycle increases the short-term attractiveness of creative intelligence. Human Nature, 17(1), 50-73.

Pinker, S. (1997). How the mind works. New York: W.W. Norton & Company.

Prokosch, M.D., Coss, R.G., Scheib, J.E., & Blozis, S.A. (2009). Intelligence and mate choice: intelligent men are always appealing. Evolution & Human Behavior, 30(1), 11-20.

Todd, P.M., Penke, L., Fasolo, B., & Lenton, A.P. (2007). Different cognitive processes underlie human mate choices and mate preferences. PNAS (The National Academy of Sciences of the USA), 104(38), 15011-15016.