How much do our genes limit free will?

Many of us believe we are masters of our own destiny, but new research shows how genes affect our behavior.

It is now possible to decipher our individual genetic code, the sequence of 3.2 billion DNA letters that is unique to each of us and forms a blueprint for our brains and bodies.

This sequence shows how much of our behavior is highly biologically predisposed, meaning that we may be prone to developing a particular attribute or trait. Research has shown that genes can predispose not only our size, eye color, or weight, but also our susceptibility to mental illness, longevity, intelligence, and impulsiveness. Such properties are written into our genes to varying degrees – sometimes thousands of genes work together.

Most of these genes show how our brain circuits are built in the womb and how they work. We can now see a baby’s brain how it’s built, even 20 weeks before birth. There are circuit changes in their brain that correlate strongly with genes that predispose to autism spectrum disorders and attention deficit hyperactivity disorder (ADHD). They even predispose to conditions that may not appear for decades: bipolar disorder, major depression, and schizophrenia.

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We are increasingly confronted with the prospect that predispositions to more complex behaviors are similarly embedded in our brain. This includes what religion we choose, how we form our political ideologies, and even how we form our friendship groups.

Nature and care are intertwined

There are other ways our life stories can be passed down through generations as well, aside from being inscribed in our DNA.

“Epigenetics” is a relatively new area of ​​science that can show how closely nature and care can be linked. It’s not about changes to genes themselves, but about the “tags” that are attached to genes from life experience and that change the expression of our genes.

A 2014 study looked at epigenetic changes in mice. Mice love the sweet smell of cherries. So when a wave hits your nose, a zone of pleasure in your brain lights up, motivating you to rush around looking for the treat. The researchers decided to combine that smell with a light electric shock, and the mice quickly learned to freeze with anticipation.

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The study found that this new memory carried over generations. The mice’s grandchildren were afraid of cherries even though they had not experienced the electric shock themselves. Grandfather’s sperm DNA changed shape, leaving a blueprint of experience entwined in genes.

This is ongoing research and novel science, so questions remain as to how these mechanisms could be applied to humans. However, preliminary results suggest that epigenetic changes can affect offspring of extremely traumatic events.

One study showed that the sons of US Civil War prisoners in their mid-40s had an 11% higher death rate. Another small study showed that Holocaust survivors and their children had epigenetic changes in a gene linked to their levels of cortisol, a hormone involved in the stress response. It’s a complicated picture, but the results suggest that offspring have higher net cortisol levels and are therefore more prone to anxiety disorders.

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Do we have leeway for free will?

Of course, it’s not just that our lives are set in stone by the brain we were born with, the DNA our parents gave us, and the memories passed down by our grandparents.

Fortunately, there is still room for change. As we learn, new connections are formed between nerve cells. As the new skill is practiced or learning is relived, the connections are strengthened and the learning consolidated in a memory. When memory is visited repeatedly, it becomes the standard route for electrical signals in the brain, meaning that learned behavior becomes a habit.

Take riding a bike, for example. We don’t know how to drive one when we’re born, but through trial and error and a few small falls along the way, we can learn to do it.

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Similar principles form the basis for perception and navigation. We create and strengthen neural connections as we move around in our environment, conjuring up our perception of the space that surrounds us.

But there’s a catch: sometimes our past knowledge blinds us to future truths. Check out the video below – we are all biased to see faces around us. This setting causes us to ignore the shadow cues telling us that it is the back end of a mask. Instead, we rely on proven routes in our brain to create the image of another face.

This illusion shows how difficult it can be to change our minds. Our identity and expectations are based on previous experiences. It can take too much cognitive energy to destroy the framework in our minds.

Elegant machines

As I explore in my last book, The Science of Fate, published last year, this research touches on one of life’s greatest mysteries: our individual decision-making ability.

For me it is nice to see ourselves as elegant machinery. Input from the world is processed in our unique brains to produce the output, which is our behavior.

However, many of us may not want to forego the idea of ​​being free agents. Biological determinism, the notion that human behavior is completely innate, rightly makes people nervous. It is abhorrent to believe that horrific acts in our history have been committed by people who have been unable to stop them because it makes them feel like they may happen again.

Maybe we could picture ourselves this way instead not be restricted through our genes. Recognizing the biology that influences our individuality can then enable us to better pool our strengths and use our collective cognitive ability to shape the world for the better.