It’s easy to get frustrated when you think you’re fighting your genetics. When it comes to things like weight issues, difficulty with alcohol, or even problems with a bad temper, you can look at your biological family and feel doomed to the patterns you observe around you. But while we do inherit genetic predispositions to certain conditions, it is actually surprising to learn how much of ourselves is not predetermined by our DNA. What creates family similarities can be influenced just as much as our biology as by the habits we “inherit” (learn without realizing it). The good news is, habits, compared to genetics, can be much more easily changed.
In biological psychology, there are calculations regarding how much of a characteristic or disease is influenced by genetics. Based on studies of families, particularly twin studies (identical twins raised together versus raised apart), a percentage of influence can be determined. This is called the Heritability Factor. Some traits, like eye color, have a high percentage, 98% in fact, meaning there is not a lot that will change our deep brown eyes. Or our freckle count (91%). But for most other traits or conditions, in looking at the list, it is quite interesting to see how much environment can have an effect. Alcoholism and Obesity both have heritability estimates of 50%. This means that while we may inherit a predisposition to these conditions, there is just as much we can do to avoid them. Even height has only a 60% heritability, meaning our nutrition and life circumstances can determine our height. (Did you know that when children are under a lot of stress, hormones that are released inhibit their growth?) Tobacco dependence is also at 60%. Surprising to me is that longevity (how long we live) has a heritability of only 26%! That means the way we live and the choices we make have a huge influence over how long we’ll be around.
In looking at the environmental influences of these conditions, however, don’t be fooled to think that we don’t “inherit” some of these, as well. In psychological terms, we very frequently inherit patterns of behaviors and ways of expressing ourselves. Unconsciously we learn to eat the way our parents eat, develop attitudes and patterns of how we drink alcohol as our families did, and even express our anger in ways that were modeled to us. In this way, while not “genetic,” we inherit tendencies that have a strong influence over our lives: how we behave, how we handle stress, how we resolve (or don’t resolve) conflict.
Often, in working with people, psychotherapists will complete a genogram. This is basically a map of who in their history married, divorced, experienced trauma such as abuse or domestic violence and had addiction or trouble with the law, etc.. It is often shocking to see what we refer to as the “intergenerational” patterns that emerge that seem to carry on as if inherited from one generation to the next. In doing such a map, it brings clarity and awareness of the patterns that set us up for our lives. This knowledge is truly empowering. It offers us a process of change, recognizing that we can be in charge of ourselves in ways that will change our destiny, and perhaps that of our children.
A lot has been learned about nutrition and well being since we were children. Times have certainly changed, as have ideas, opportunities, and attitudes. What your parents did may have been the the best thing at the time, but may not be right for you now. So for whatever challenge you are working with, look at what you may have inherited both biologically, but also in terms of habits and attitudes. What works, and what would you like to change? You may have your father’s eyes and your mother’s freckles, but you don’t have to have their high blood pressure or smoking habit.