15 March 2015

Evolutionary psychology: understand culture and improve your life

Why do cultures in Europe differ a lot from north to south, but much less from east to west? Does it have something to do with temperature? Why are societies that are surrounded by more bacteria and viruses less tolerant and more xenophobic? And why are symmetric objects considered beautiful all over the world?

To answer these questions, we need to look into our evolutionary makeup. The mind is not just a product of culture, but also a product of evolution and environmental factors other than culture.

Massive modularity of our brains

Many families have children as well as pets, for example a dog or a cat. Even though the pets and children live in the same environment, only one species learns the language spoken in the family. Some people claim that it's because of an all-purpose learning device in our brains, but that is false (see here and here). We have pre-programmed mechanisms (also called modules) in our brains that are designed to learn a language.

We can think of the brain as a computer that is loaded with many useful programs and libraries that learn from the environment. We have mechanisms for face recognition, short-term memory, naive physics, cheater detection, incest avoidance, naive psychology, food disgust, general intelligence, etc. If you lack a module in your brain, you can't circumvent it by learning; the same way you can't fly or breathe under water, because you lack important body parts. Cats and dogs won't be able to talk to us unless their brain evolves and after a stroke you might lose the ability to talk coherently. Malfunctioning brain mechanisms are also the root causes of disorders like Down syndrome, Asperger syndrome and prosopagnosia.

Rider on a elephant

A very useful metaphor about our brains comes from Jonathan Haidt's excellent book Happiness Hypothesis. Our brains consist of a rider controlling an elephant (Daniel Kahneman uses System 1 and System 2 for essentially the same thing). The elephant is responsible for our emotions, intuition, bodily functions, etc. The rider is responsible for rational thought, self-control, etc. The elephant has very old parts that we inherited from reptiles and mammals, while the rider is very young and is also present in higher mammals.

Ironically, the rational and younger rider thinks that he has full control, while it's often the elephant who makes the big decisions. The rider has only a limited power against the strong elephant. Imagine you heard about an excellent work opportunity, but later decided that commuting 10 more minutes to work is not worth more salary and better work conditions. The elephant was very scared and wasn't going anywhere, so the rider came up with his own story where he has everything under control.
The first principle is that you must not fool yourself—and you are the easiest person to fool. – Richard P. Feynman

Nature versus together with nurture (and randomness)

You know the classic question: is behavior X determined by biology or is it determined by the environment? This question gives the impression of there being only two alternatives, a notion now recognized as a false dichotomy. Robert Sapolsky said it well.
To an overwhelming extent, the age-old “nature versus nurture” debate is silly. The action of genes is completely intertwined with the environment in which they function; in a sense, it is pointless to even discuss what gene X does, and we should consider instead only what gene X does in environment Y. – Robert Sapolsky in Peace Among Primates
An important, but often overlooked, factor is randomness. We have chemical processes running in our bodies that are inherently random and those random events affect our behavior. There is also randomness in people's lives—two people will never go through the same experiences. Randomness is one of the reasons why identical twins raised by the same parents in the same environment end up being slightly different. Another overlooked factor is prenatal environment. What your mom ate and whether she was stressed out during pregnancy affects your behavior forever.

An example of how all this plays out is our status-seeking behavior. We all have a brain mechanism that scans the environment around us, measures our own social status and tries to increase it. Entrepreneurs improve status by starting a successful company, professors by getting their papers published and a hunter-gatherer perhaps by killing a big animal. A basic behavior is provided by nature and then culture and environment shape it into its final form. Note that there are also gender differences, men and women on average seek status differently.

Many people have small jaws these days and therefore problems with teeth not fitting in. It is unlikely that this is caused by bad genes, since only 10 000 years ago people had bigger jaws with better teeth. Scientists theorize that it was because they chewed harder food, while these days it's mostly soft food, so the jaw doesn't develop properly. Our brain is much like the jaw. Overprotected kids suffer a deficit of play and they grow into less creative, less social and less happy adults. Even if a behavior is influenced by genes, the genes need input from the environment for the behavior to develop properly. Nature and nurture are truly inseparable.

Evoked and transmitted culture

Have you ever wondered why nations in colder areas have tasteless food? The classic explanation attributes this to cultural differences. This politically correct answer is completely useless: cultures are different because they are different (although it would be appreciated in the tautology club).

People in warmer regions used spices, because they had to. The commonly used spices have very good antimicrobial properties, so they protect food from spoiling when it's too warm.

Let's now move on to a much more difficult topic than food, namely xenophobia. What you read next might be upsetting, so watch a video of a cute duck first.

Our brains are also pre-programmed to be xenophobic and intolerant, but it seems to be very dependent on the environment around us. Suppose you are a hunter-gatherer living in the mountains. The spring and summer were surprisingly cold and the food is scarce, so you descend from the mountains where you meet another tribe. The tribe has been living in an environment with different pathogens (bacteria, viruses, parasites), so you are not immune to them but they are. Exposure to those pathogens might harm you and even kill you. What might evolution do? It makes you avoid strangers, because they might carry dangerous pathogens. It also makes you avoid new things and be more conservative, because your old ways of living are proven to be safe. Remember that evolution is an amoral process that only cares about transmission of genes, so it sometimes leads to such unpleasant results.

There is also good news, though. People living in areas with fewer pathogens are less xenophobic, more tolerant and open to new experiences. If you live in a safe environment, it's less likely that a contact with a stranger or a new experience will harm you. Rather than avoiding strangers, it's more beneficial to meet them and perhaps trade goods with them.

All of this sounds reasonable, but did we really evolved to be this way? One can do experiments to confirm the theory. In one experiment, people that heard news about a recent disease outbreak were less open to immigration. Unfortunately, it's hard to do experiments with whole cultures, but we can wait for a natural experiment: different parts of the world get rid of pathogens quicker than others, so we can compare how their levels of xenophobia change over time.

Wait, there is more! Countries with lower prevalence of pathogens also value physical beauty less, have puberty earlier, are more individualistic, have higher IQ, are less violent, are more democratic, have fewer kids, etc. The list is never-ending and it remains true even after controlling for factors like wealth and temperature. Prevalence of pathogens might be the most important factor behind cultural differences. It will take decades to prove causality and not just correlation, but it's very intriguing nevertheless.

In the last 100 years, humanity made a lot of progress; many countries ended racial segregation, gave voting rights to women and are now even considering gay marriage. What if this increased tolerance happened due to progress in medicine, vaccination and better hygiene? This social change is often attributed to our rational selves, but perhaps we only tamed the elephants in our brains.

Other environmental factors that correlate strongly with cultural differences include: temperature, abundance of resources, ratio of men and women, whether they have a nomadic lifestyle, etc. When elements of culture are shaped by the environment, they are called evoked.

People in warmer cultures don't need to use spices anymore, because they have fridges, but such recipes are still used by new generations. Old information is being transmitted, so we call it transmitted culture. It is unclear what elements of culture are evoked and which are transmitted, though. The understanding of our brains is limited, so anyone claiming they completely understand culture is lying.

Improve your personal life

We could apply evolutionary theories to social problems, but I like to use them to improve my own life. Most people who tried public speaking felt nervous about it. Someone then told them to just relax and not think about it. However, this well-intentioned advice only focuses on the rider and completely ignores the elephant in the brain.

What if I told you that a better strategy is to stand straight instead? Your body will lower the level of stress hormones, the elephant will feel less scared and the rider will calm it down easily.

Other life improvements are about the new media: celebrity tabloids, video games, TV, novels, movies and porn. Recall that our genes react to the environment around us. What happens if you spend your free time fighting fictional creatures or watching lives of attractive people that are 5 000 kilometers away? Your behavior in the actual culture you live in will be inappropriate and suboptimal.
From Stuff No One Told Me

I'm not saying you should avoid all the new media completely. For example I read novels and watch movies from time to time, but I try to pick the more realistic ones. However, you should avoid porn and celebrity gossip like the plague. On the other hand, feel free to gossip about the people around you or have sex with them—science has shown that both behaviors are beneficial.

There are plenty of other ways to apply evolutionary theories to your life and if you want to know more, see the reading list at the end of this post. The possibilities are truly endless: you can improve your happiness, make better decisions, lower your stress, become a better writer, become healthier, be more efficient or understand your own gender better.

New theories

Evolutionary psychologists have come up with interesting theories that try to explain many facts of human existence.
  • Why people gossip.
  • Why socialism works in a family or a small community, but ends in a disaster when applied to a whole nation. As E. O. Wilson said, "Marxism: wonderful theory, wrong species".
  • Why toddlers are almost indistinguishable from each other.
  • Why women put on make-up and why men take large risks.
  • Why parenting style has almost no effect on a child's personality (parents affect child's personality through their genes instead).
  • Why a small fraction of people is born left-handed.
What if some of the theories turn out wrong? We move on and try to find better explanations. However, some of the theories have already amassed substantial evidence, so they are very likely to be correct.

Interestingly, scientists have failed to provide good evolutionary explanations for humor, male homosexuality, female orgasm and music. Music might be just a by-product of evolution that presses the right buttons all over the brain. Think of it as a pleasurable drug.

Some (flawed) arguments against evolutionary psychology

If behaviors like aggression, psychopathy and xenophobia are encoded in our genes, people think this will give others excuses. You can't kill a person, blame it on your genes and skip going to jail. Since the science can be misused, some people try to stop this line of research. Their flawed reasoning reminds me of my favorite quote.
Numerous studies have shown that at least 98% of murderers were born after a heterosexual intercourse. That's why the European Union should ban people from having sex. – Martin Malý
We could ban sex to end all human suffering, but it would come with at a big price: all the good things human would be gone too.

Mentioning evolutionary psychology or neuroscience often leads to very heated discussions, comparable to those about politics and religion. The new scientific findings affect every single mainstream ideology; it doesn't matter whether you are on the political left or right, an anarchist, a feminist, a Christian or even a vegetarian. Each ideology got something wrong about our minds and bodies.

Some people devoted their lives to an ideology, built their whole identity around it and it's hard for them to admit they were wrong the whole time. Cognitive dissonance then kicks in and people get upset. Many arguments against evolutionary psychology have more to do with emotions rather than objective facts.
Rationality is costly. It prevents us from believing what we want to believe. – Michael Huemer in The Irrationality of Politics


It has been 150 years since Charles Darwin's book On the Origin of Species and people are slowly accepting that evolution is real. However, most people have still trouble accepting that evolution affects our brains too. Many religions have accepted evolution and it's time for the rest of the world to do the same.

I would like to end the post on a positive note, so let me quote Daniel Dennett.
Every living thing is, from the cosmic perspective, incredibly lucky simply to be alive. Most, 90 percent and more, of all the organisms that have ever lived have died without viable offspring, but not a single one of your ancestors, going back to the dawn of life on Earth, suffered that normal misfortune. You spring from an unbroken line of winners going back millions of generations, and those winners were, in every generation, the luckiest of the lucky, one out of a thousand or even a million. So however unlucky you may be on some occasion today, your presence on the planet testifies to the role luck has played in your past. – Daniel Dennett in Freedom Evolves

Further reading and watching

Videos and lectures

The easiest way to start with evolutionary psychology is by watching videos and lectures. It's possible to watch them 25% faster by using the gear button on YouTube.


These books take into account evolutionary psychology and neuroscience. Many of them aren't solely about evolution, but they are based on the newest research.

Some interesting papers

If you feel adventurous, you can read some scientific papers.