Nature, Nurture, and Randomness: Part 1

Posted by Andrew on Jan 1, 2018 in Science

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I’ve written a few blogs on what I’ve learned from Robert Sapolsky. He’s a behavioural biologist at Stanford University who has spent decades living around and studying primate species like baboons. This has improved his knowledge of human behaviour, along with what he calls “different buckets” of information. They include fields like neuroscience, evolutionary psychology, genetics, anthropology, sociology, and endocrinology. In his lectures, and in his new amazing book called Behave, he explains the pros and cons of different reasoning methods in each bucket. Sapolsky does a great job of elaborating in detail on the incompatibility of some assumptions in different fields. He also talks and writes about how you can combine the accurate bits of knowledge to explain behaviour in understandable terms. Here are the links for my previous blogs about his work, called Are Men Actually Better at Math Than Women?, and There Are People Born as Both Male and Female Who Are Not Hermaphrodites:

Are Men Actually Better at Math Than Women?

One idea that I recently heard Robert Sapolsky discuss adds another layer of complexity to what I’ve thought for a long time. That’s always an enthralling experience for me. I had arrived at an important lesson through many years of learning about psychology and evolution. This is that the answer to the nature vs. nurture question is always a complicated mixture of both factors. Evolved genes in our biology play important roles in explaining human behaviour. But our prenatal, childhood, and cultural upbringings in our environments have huge influences on genetic expression.

We are all genetically programmed with unique characteristics. However, genes can be turned on or off depending on how our brains think we should adapt to our environments. Someone who has genes associated with musical skill might not achieve their potential if they live in a poor neighbourhood and have a low socioeconomic status. They could end up in a completely different career and adapt their personality to that because they were never able to afford a musical instrument or lessons. Twin studies famously show the power of evolutionary and genetic influence. But twins with different upbringings sometimes choose entirely opposite careers and lifestyles. Let’s assume that both twins have genetic musical skill. If the second one grows up in a high socioeconomic status, he or she will have a much greater ability to become a musician. However, this might be hindered by the parents’ values. If they see no hope for a career as an artist, then that rich kid could easily take a path that is completely different from music.

Robert Sapolsky taught me that something more than nature and nurture is responsible for the complex factors that construct human behaviour. It’s not just nature and nurture. It’s nature, nurture, and randomness. Genes and environment play massive roles. But there’s a crucial third piece to this puzzle, which is randomness.

Basically, you can analyze and predict how genes and environment affect behaviour to an extent. We can understand where our genes came from and how they shape us because most of us probably know our parents. Science can explain how evolution constructs genes, and how they can influence the people we become. But our experiences within our cultures are much more difficult to trace. We can’t really predict what is going to happen to us in the future because there are so many complex variables. No one can tell us who we’ll meet, what relationships will form, or how they’ll shape our personalities and the paths we take in life. A lot of scientific study has been done on how our interactions with our environments impact genetic expression. There’s an entire fascinating field surrounding this idea that’s called epigenetics.

But when you take people out of the confines of laboratory experiments, scientists have exponentially less control over how cultures impact behaviour. Life is a hell of a lot more complicated than genes. Like any self-respecting scientist will tell you, there’s waaaay more individual variation than there is between different groups of people. For one thing, the cultural and childhood upbringings of all of our ancestors changed their genes. Evolution selected for pieces that made up the genes that were given to us by our parents. You can’t escape environmental effects, and like I said, they’re pretty random. They’re even more outside of our control than how evolution constructed our biology. There’s an entire field of science devoted to studying how culture affects evolution, called sociobiology.

…To Be Continued…

Originally published at on January 1, 2018.