Social media algorithms, artificial intelligence, and our own genetics are among the factors that affect us beyond our consciousness. This begs an old question: are we in control of our own lives? This article is part of The Conversation’s series on the science of free will.
Many of us believe we are masters of our own destiny, but new research shows to what extent our behavior is influenced by our genes.
It is now possible to decipher our individual genetic code, the set of 3.2 billion DNA “letters” unique to each of us, that forms a blueprint for our brain and body.
This series shows how much of our behavior has a strong biological predisposition, which means that we may be skewed in developing a particular attribute or characteristic. Research has shown that genes can be susceptible not only to our height, eye color or weight, but also to our vulnerability to mental health problems, longevity, intelligence and impulsivity. Such traits are, to varying degrees, written into our genes – sometimes thousands of genes work together.
Most of these genes indicate how our brain circuit is established in the womb and how it functions. We can now see a baby’s brain as built, even 20 weeks before birth. There are circuit changes in their brains that strongly correlate with genes prone to autism spectrum disorder and attention deficit hyperactivity disorder (ADHD). They even predispose to conditions that may not occur in the next few decades: bipolar disorder, major depressive disorder, and schizophrenia.
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We are increasingly confronted with the prospect that a predisposition for more complex behavior is in the same way in our brains. These include which religion we choose, how we shape our political ideologies and even how we create our friendship groups.
Nature and education are intertwined
There are other ways in which our life stories can be passed down from generation to generation, besides being incorporated into our DNA.
“Epigenetics” is a relatively new field of science that can reveal how intertwined nature and education can be. It doesn’t look at changes in genes themselves, but instead looks at the “tags” placed on genes from life experience that change how our genes are expressed.
A 2014 study looked at epigenetic changes in mice. Mice love the sweet scent of cherries, so when a tinge reaches their nose, a pleasure zone in the brain lights up, motivating them to run around and chase the treat. The researchers decided to combine this odor with a mild electric shock, and the mice quickly learned to freeze in anticipation.
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Epigenetics: How Does It Affect Our Psychology?
The study found that this new memory was passed down from generation to generation. The grandchildren of the mice feared cherries, even though they themselves had not experienced the electric shocks. The grandfather’s sperm DNA changed shape, leaving a blueprint of the experience entangled in the genes.
This is ongoing research and new science, so questions remain about how these mechanisms may apply to humans. But preliminary results indicate that epigenetic changes can affect the offspring of extremely traumatic events.
One study found that the sons of Civil War inmates had an 11% higher death rate by their mid-40s. Another small study found that Holocaust survivors and their children carried epigenetic changes in a gene related to their cortisol levels, 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 susceptible to anxiety disorders.
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Do we have room 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 from our grandparents.
Fortunately, there is still room for change. As we learn, new connections arise between nerve cells. As the new skill is practiced, or the learning is relived, the connections become stronger and the learning consolidated into a memory. When the memory is visited repeatedly, it becomes the brain’s default pathway for electrical signals, meaning learned behavior becomes a habit.
Take bicycles for example. We don’t know how to drive one when we’re born, but through trial and error, and a few minor crashes along the way, we can learn to do it.
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Similar principles are the basis for both perception and navigation. We make and strengthen neural connections as we move through our environment and evoke our perception of the space around us.
But there is a catch: Sometimes our previous lessons blind us to future truths. Watch the video below – we are all keen to see faces in our environment. This preference causes us to ignore the shadow cues that tell us this is the back of a mask. Instead, we rely on proven pathways in our brain, which generate the image of another face.
This illusion illustrates how difficult it can be to change your mind. Our identity and expectations are based on past experiences. It can take too much cognitive energy to break the boxes in our mind.
Elegant machines
As I explore in my latest book published last year, The Science of Fate, this research touches on one of life’s greatest mysteries: our individual capacity for choice.
For me, there is something beautiful about seeing ourselves as an elegant machine. Input from the world is processed in our unique brain to produce the output that is our behavior.
Many of us may not want to give up the idea of being free agents. Biological determinism, the idea that human behavior is completely innate, makes people justifiably nervous. It is disgusting to think that heinous acts in our history were committed by people who were unable to stop them, because that evokes the ghost that they could occur again.
Maybe we could think of ourselves as not be limited through our genes. Recognizing the biology that affects our individuality can then allow us to better pool our strengths and use our collective cognitive ability to shape the world for the better.
This article by Hannah Critchlow, Science Outreach Fellow at Magdalene College, University of Cambridge, has been republished from The Conversation under a Creative Commons license. Read the original article.
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