- Scott H Young - https://www.scotthyoung.com/blog -

Genes and Free Will

How important are your genes? If your genes determined most of your life outcomes, would that mean you have more or less control over your life?

The answer to the first question, at least with respect to a lot of traits, seems to be fairly important. Researchers using various techniques (such as identical twins separated at birth), have found a huge variety of important life dimensions can be explained by differences in genes: intelligence [1], criminality [2], income [3], personality [4], self-discipline [5], etc.

This isn’t without controversy, and opinions on this research run from the extremes of nearly genetic determinism, to the opposite with some researches like Anders Ericsson [6] denying the importance of natural endowments at all.

I’m not qualified to adjudicate such a debate, suffice it to say that although there is some controversy, it’s fairly safe to say that genes matter a little, and it may be that they matter a lot.

Instead of trying to weigh the evidence, let’s simply imagine that genes do matter a lot. That genetic differences explain 80% of your IQ, personality and happiness in life. Should this make us feel elated or despair?

Would Environmental Determinism Be Any Better?

Consider the opposite claim: that environment, not genes, determines all of our results in life. Is this a happier state of affairs?

Not necessarily.

As biologist Matt Ridley explains in Genome [7],

“There has been a long tradition among a certain kind of science writer to say that the world of biology is divided into people who believe in genetic determinism and people who believe in freedom. Yet these same writers have rejected genetic determinism only by establishing other forms of biological determinism in its place—the determinism of parental influence or social conditioning. It is odd that so many writers who defend human dignity against the tyranny of our genes seem happy to accept the tyranny of our surroundings.”

Genetic determinism may sound bad, but the alternative—that our lives are ruled entirely by the circumstances surrounding us—sounds pretty depressing to me.

If environmental determinism were true, it would mean that circumstances were destiny. Grow up poor, have an abusive parent, get the wrong 3rd grade teacher and you have no control over the outcome of your life. Genes controlling our lives sounds bad, but ceding control to the environment hardly seems better.

But what about free will or personal choice? It certainly doesn’t appear in any of the scientific measurements of genetic contribution to certain traits.

It’s not as if scientists, doing a study of the genetic contribution for IQ, note that 60% is explained by genes, 20% by environment and 20% by free will. The latter term, if it exists, doesn’t show up as a component of the measurement. It’s not clear that, if there is some wiggle room for human agency, it necessarily exists in the space left over after you account for genes.

Where’s the Free Will?

The existence of free will is even more contentious than genetic determinism. Many people flatly deny it exists [8], or even that it’s a sensible concept.

Hardcore materialists will argue that belief in free will is equivalent to belief in the supernatural. Everything follows the laws of physics, including human beings. Therefore human actions are explainable in principle (if not in practice) by the rules of physical laws. There’s no place in Einstein or Maxwell’s equations for free will, so therefore it cannot exist.

Compatibalism [9], on the other hand, argues that, yes, although the entire world may be reducible down to physical laws, free will is still a useful concept. There’s a difference between an action people normally presume I have control over, say getting out of my seat to turn off the light switch, and one I don’t have control over, such as stopping my heart from beating voluntarily. Even if, with omniscient knowledge of physics and particle positions, I could predict with certainty that I, in fact, won’t turn of the light switch, it’s still useful in practice to consider it differently from stopping my heart voluntarily or transforming into a unicorn.

In this argument, I side with the compatibalists. Many human-level concepts, don’t have perfect coherence in a physical level, but they are useful terms that permit intelligent reasoning about many situations beyond a few edge cases. Interestingly, in a survey of professional philosophers [10], the overwhelming majority lean towards compatibalism rather than the hardcore materialist/supernatural stances.

So, for the sake of continuing my argument, let’s imagine that free will exists.

Is There Free Will in the Genes?

If you’re following up to now, there’s two contentious assumptions I’ve made: one that genes have a non-negligible explanatory power on our lives and, two, that compatibalist free will exists.

Now, the follow-up question is: would we want things to be more “genetic” or “environmental” to maximize this compatibalist definition of free will?

I don’t have an exact answer to this question, but I do think the default intuition is probably misleading. That intuition is that genes, those unseen, chemical constituents that exist in all of our cells, can’t possibly contribute to greater free will, no matter your definition of it. After all, how can something that was determined before I was born possibly increase control over my life?

However, this intuition rests on the implausible assumption that free will exists outside of the causal structure of the universe. It’s entirely possible, and indeed necessary, that an action we consider having free will in nature, will have a unfree cause. Life has only existed on earth for a few billion years, whereas the universe is much older. Since previous events in time cause future events, every event that is happening now (free will or not) must have been ultimately caused by the outcome of physical laws that existed prior to there being human beings or sentient life. Therefore, if my decision to turn off the light switch does have something we could usefully call free will, that “free will” must have been caused by something which we wouldn’t think of as having “free will”.

So the intuition that genes can’t contribute to free will is only true if nothing can contribute to free will because it doesn’t exist.

If, however, genes cause something which enables us to make choices we normally consider to be “free will” then the fact that a certain attribute is highly genetically determined is not actually evidence that it’s a less free choice. The truth may be the opposite, with genetic endowments contributing to free will and environmental influence making people less free.

Imagining Genetic Free Will

Let’s imagine, for instance, that genes do in fact causally create the kind of situations we normally regard as being freedom. What would that look like?

Side note: For those keeping score at home, we’re now up to three contentious assumptions. First, that genes have sizeable impacts on our lives. Second, that compatibalist free will exists. Now, third, that genetic influence is causally associated with increased freedom. Depending on your likelihood estimate of these three assumptions this part may either seem entirely reasonable or completely absurd.

Your genetic code serves as the recipe book for the proteins that make up your brain and body. They not only determine your physical features, but also how your brain is wired together. Even if the instructions aren’t precisely specified, they could be specific enough that, barring extreme circumstances, your brain will grow in a particular sort of way.

In my case, I’m prone towards bursts of obsessive interests. In addition to projects like the MIT Challenge [11], which have taken that learning obsessiveness to an extreme, I would go through phases as a child where I’d become intensely interested in everything from dinosaurs, to geology to astronomy.

Interestingly, my grandfather had exactly the same nature. An engineer by profession, he would go through bouts of extreme interest in various hobbies and pursuits throughout his life—woodworking and construction (he built two houses), jewelry making and golf. He even developed an obsession for computers in his eighties.

Now this could just be a coincidence, but I’m inclined to believe that there was something genetic that caused the brains of both myself and my grandfather to have this pattern of interested obsessions.

In both our cases, our interests were a full expression of our preferences. We like learning new things, and when we start, we tend to get quite involved. Nobody forced us to pick up certain hobbies, the expression of these preferences were as natural as my turning off a light switch.

Genetics may have caused us to have a particular preferences and general tendencies towards interests. This then led us to certain patterns of obsessively getting interested in particular hobbies or subjects. The genes didn’t coerce us into having a particular response, but rather they were responsible for making us into the kind of people we are, the kind of people who later make choices in a certain way.

How Important is Genetic Free Will?

Imagine two opposing scenarios, both in which our lives are entirely decided by our genetic codes, but that have exact opposite implications for freedom.

In one world, human preferences are more or less exactly the same. We all want exactly the same things in life, like things equally and have the same dreams and goals. Genes only influence our fixed abilities and capacities to achieve these same ends. In this world, genetic determinancy means a lack of any free will. Any difference between us is simply because you can do things I can’t, or vice versa.

In a different world, human abilities are more or less exactly the same. We all have the same ability to do everything, but our preferences differ wildly. Some of us want to work hard and become rich, others want to relax and enjoy a simple life. Some want fame, others want quiet. In this world, genetic determinancy means complete freedom. The differences between peoples lives come about because genes made them into different kinds of people with different preferences. Once these preferences are known, people pursue them without hindrances.

The most reasonable position is that genes influence our abilities and our preferences, and are, perhaps, the major contributing factor for both of these. Abilities and preferences are probably not even causally separable, at any rate. (Does people enjoy basketball because they’re athletic, or are they athletic because they enjoy basketball? Both answers might be simultaneously true.)

Do genes mostly constrain abilities, and therefore limit freedom? Or do they mostly cause preferences, and therefore enhance it? I honestly have no idea.

What I do feel is that the default intuition and talking points about the prevalence of genetic explanations for life is probably wrong. Genes, if they do have a large role in your life outcomes, do so by making you the kind of person that you are—not only shaping your abilities, but also what you like, love, dream and wish for.