Luck of the draw: How the random results of the genetic lottery can influence a host of your life’s outcomes – Milwaukee Journal Sentinel

Philipp Koellinger| Milwaukee Journal Sentinel

Here is a thought experiment for you. How much praise do you deserve for the good things that have happened in your life? And how much blame do you deserve for the bad? As a scientist who specializes in social genomics the study of how the interplay of genetics and social environments influences our lives I argue that much of what happens to us in life is really a matter of luck.

Many types of luck affect our lives: who our parents are; when and where we are born; whether the tornado that passed through our hometown hit our house or not. All of these types of luck are beyond our control. And yet, they shape who we are and what happens to us throughout our lives.

One fundamental example of luck is the set of genes we get from our parents. Everyone starts with a random combination of their parents genes that are fixed at conception and remain unchanged from that day forward. In other words, we get our start in life through a genetic lottery in which many outcomes are possible, but only one materializes.

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The results of this lottery have a big effect on your life. But they dont control everything. The relationship between our genes and the shape of our lives is far more complicated than that.

Lets start with what our approximately 22,000 genes do control. Among other things, they determine whether were born in a male or female body, if our eyes are blue or brown, and if we have freckles.

Genes also influence other things, such as how tall well grow and whether were prone to obesity, cancer, dementia, or other health conditions much later in life. We say genes influence rather than control these outcomes, because other factors like the quality of healthcare we receive in childhood and whether we eat enough good food in our early years also play a part.

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The influence of genes also extends to the human brain, which is probably the most complex organ that exists in any living creature on our planet. More than half of our genes seem to influence the brain in one way or another. They pre-wire the brain, and then our experiences and activities throughout childhood and adulthood rewire and adapt this amazing organ to our circumstances.

A useful analogy is to think of the brain as a book with thousands of pages. When were born, the book has chapter names and preliminary notes and themes scribbled throughout. As we grow up, we fill in the blanks with what weve learned and experienced. Sometimes, an entire chapter of the book may be erased or rewritten (perhaps because of a stroke or injury). But, for the most part, the main themes of the original book continue to develop throughout our lives.

The partial influence of genes on virtually every aspect of who we are is so well-known that scientists started referring to it as the first law of behavioral genetics. In the past few years, tremendous technological progress has made it possible to read a persons genetic code reliably, quickly, and inexpensively. This allowed scientists around the globe to collect samples of genetic data from millions of people. My team and our colleagues used that data to look for associations between genes and the many behavioral and socioeconomic outcomes such as educational attainment, risk-taking, happiness, or alcohol consumption.

Our results reliably show that genes seem to influence all of these outcomes. And yet, there is no single gene that makes a person smart, or start a business, or reach for a bottle of wine the moment they get a chance to do so. My teams research tells us that the real story is more complex and subtle than anyone would have thought just a few years ago.

It turns out that most outcomes are influenced by thousands of genetic variants, each of which has only a tiny effect by itself. But adding up all these tiny effects begins to explain a substantial part of the differences among the people we observed. We call some of these differences such as whether people go to college or are willing to take risks genetically complex traits because they are linked to a large number of genes and because the biological function of those genes is often still unknown.

Adding to the complexity, most genes influence more than one outcome. We found that some of the genes associated with educational attainment are also related to health outcomes such as dementia, cancer, and cardiovascular diseases, but we dont know why exactly. It could be that some genes that make us perform well in school early in life also protect our brains later in life from cognitive decline. It also may be that the protective effect of these genes actually works via schooling. Maybe a better education helps you afford a healthier lifestyle and also leads to a challenging job that requires you to exercise your brain constantly, which in turn may reduce the chance of being diagnosed with dementia later in life.

We still have a lot to learn. For example, how do genes and environments interact to give rise to the behaviors and traits we observe in people later in life? But one thing we already know for sure is that behavior and health are tightly related, and that these links can often be traced back to the specific genes we were born with, at least to some extent.

My long experience studying how life outcomes are affected by the random results of our individual genetic lottery makes me feel humbled by the good things that have happened to me. It also makes me skeptical when others claim that they deserve something or when they blame bad fortune on the person unlucky enough to be its victim. Instead, I find that modesty and sympathy for others are the most natural responses to the lessons that modern genetics continues to teach us.

Philipp Koellinger is a professor of public affairs at theLa Follette School of Public Affairs, University of Wisconsin-Madison.

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Luck of the draw: How the random results of the genetic lottery can influence a host of your life's outcomes - Milwaukee Journal Sentinel