Human behaviours explained by Evolution

Sara Polakova

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The weird and wonderful aspects of human behaviour have fascinated science for centuries. More recently, the fields of evolutionary science and cognitive anthropology have focused on explaining the exact mental mechanisms which have been subject to evolutionary pressures and have developed into specific traits and behaviours. This particular academic perspective is called Evolutionary Psychology, and while slammed by some academics to be deterministic and giving no space to free will, it sheds an interesting light on some of humanity’s most peculiar obsessions and traits.

1. Fairy tales

Red Riding HoodCinderellaSleeping Beauty and other fairy tale classics are not just a narrative coincidence. Pioneer of Structuralism Levi-Strauss argued that fairy tales all have common themes (betrayal, winning the damsel, a villain plotting to outsmart the hero etc.) which are a result of the way our brains are wired. This is further supported by Universalist linguists (people who believe all languages have universal underlying structures), such as Noam Chomsky, who argue that the way we speak, put together sentences and ultimately construct themes is a result of millions of years of evolutionary pressures.

2. Fear of snakes

Scientists studying phobias postulate that there are common fears which seem to be genetically ingrained in the human genus. One of them is the fear of snakes, which has been demonstrated not only in monkeys (monkey babies raised in captivity automatically running away when presented with rubber snakes) but has also been noted in human children (and many adults!). The evolutionary explanation is relatively simple; since most snakes are deadly to humans, a natural, ingrained fear of them is a savvy survival mechanism.

3. Suspicion of strangers

Remember when mum told you to beware of strangers when you were little? Turns out you would have probably figured it out on your own. The hormone Oxytocin (which is instrumental in helping us bond with people and is even sometimes called the ‘Cuddle Hormone’) can equally cause us to distrust people we don’t know. This has been demonstrated by several studies; one of them showed people who inhaled oxytocin (versus a placebo hormone) would either cooperate more with people they knew, or cooperate less with people they don’t know when they were instructed to carry out a group task. This has the potential evolutionary explanation of having a chemical tool to bond well with people in your intimate circle/tribe, but be wary of (and hence likely increase survival) of unknown individuals from other tribes.

4. Scratching

Okay, perhaps not the most glamorous thing evolution gave us, but whether it’s scratching a mosquito bite or scratching underneath that itchy polo neck, there is a genetic reason to explain why we do it. The itching sensation is something that our bodies use as a way of eliminating potentially harmful irritants or indeed anything that could bite us, infect us or harm us in any way.

5. Laughing

Humans are not the only ones who laugh. Bonobos and other primates demonstrate similar hooting noises when amused by play and frolic and do it in a very social context where a whole group participates in the ‘laughter’, in a similar contagious fashion to people laughing at a stand-up gig. Robin Dunbar of Oxford University considers laughter to be a sophisticated ‘psycho-pharmaceutic’ – a social tool for cohesion, cooperation and a positive mentality.

Moreover, laughing with another human often suggests playful intent and therefore generates trust and a firmer social bond. The evolutionary importance of laughter in terms of social cohesion is further demonstrated by experiments showing humans are much less likely to laugh when alone. This doesn’t go for just laughter though; Dunbar (and other academics such as Bosson) attribute this ‘psycho-pharmaceutical’ social bonding characteristic to gossip as well.

6. Liking puppies (neotony)

Well, not just liking puppies – liking anything cute that looks neonatal (i.e. very young, just born). It’s hotly debated as to why evolution shifted us in this way, but the fact that you are likely to swoon when presented with a picture of a kitten is no coincidence. In fact, research suggests that humans favour (and even sexually select for, particularly with females) juvenile characteristics. And it’s not purely a human trait; neotony is a phenomenon common across the animal kingdom, with the Axolotl salamander being an extreme example; they remain in tadpole state for their entire life! Why this is, we are yet to discover; whether it is that looking young ensures you more social protection (connotations of fragility), facilitates social bonds or even makes you more likely to reproduce, it’s a fascinating evolved aspect of human behaviour.

7. Cuddling

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The same hormone that makes us distrust strangers also gives us a rush when we hug or cuddle someone, and is also responsible to the immediate new-born baby instinct to cuddle up to its mother to suckle milk. Oxytocin is a hormone of attachment and trust and helps social cohesion; you can often see primates grooming each other in nature and mothers cuddling their offspring; the reason for that is evolutionary. It helps to strengthen bonds and relationships which was very much needed for our ancestors to survive and be able to form primeval families and circles of trust. So cuddle up!

8. Blushing

Honesty gets you far in life and deception and trickery is wrong. This isn’t the moral of a story in a children’s book – it’s what evolution dictates. ‘Blushing’ is nature’s way to help others pinpoint a liar in the group. Research has demonstrated that blushing is a subconscious cry for sympathy because the subject is ashamed or apologetic about deceiving their surroundings. Tests in this research study actually showed that people tended to sympathise with ‘blushers’ more than with remorseless individuals who showed no sign of change; perceiving them as unnatural and assuming them psychopathic. So while blushing is a protective mechanism in a way, it also helps us pinpoint the real culprit behind the missing lunch from the office fridge.

9. Plastic surgery

Altering one’s body in various ways is a practice that goes back millennia. Ancient Egyptians were somewhat vanilla with their eye kohl and the occasional tattoo, whereas some sub-Saharan tribes practice teeth-removing and scarification which are incredibly painful procedures. Is this universal addiction to changing one’s look evolutionarily-driven? Many studies suggest it is. Diana Zuckerman, president of the National Research Center for Women & Families, suggests that in the 21st century Western context, thinner people have a better chance of landing a promotion and that attractive salesmen have higher success in business. This is just the tip of the iceberg and goes a lot deeper into both nature and nurture; whether the ideal is to be plump or slim, blond or brunette, tattooed or not, modifying one’s body to the cultural norm is the basic evolutionary need to belong and fit the social trends around you.

10. Gambling

This highly dangerous addiction is not just something seen in Vegas casinos.Monkeys have been shown to gamble as well, and get visibly frustrated whenever they are losing. The study demonstrated that even when the monkey’s chance of winning the juice at hand diminished significantly, they carried on gambling with increasing irrationality; very much what happens in humans too. Luke Clark of Cambridge University showed that almost-winning activities (which gambling inevitably is because it’s predominantly luck-based) encourage the brain to carrying on gambling. Hence gambling is such a dangerously addictive activity. It’s uncertain why evolution shaped our brains like that, or whether it’s simple a by-product of other behaviours (such as risk-taking). What’s for sure though, is that next time you buy a lottery ticket, the purchase is underpinned by millions of years of cognitive evolution.