DNA determines features like eye color and height as well as susceptibility to certain diseases. Does it also influence happiness?


“Yes, it can,” said Oklahoma Medical Research Foundation scientist Christopher Lessard, Ph.D. “But that’s not all there is to it.”


Researchers at Edinburgh University studied fraternal and identical twins and found that genetics are responsible for about half of our happiness. That includes traits, like being laid-back, as well as the creation of chemicals the human body uses to influence happiness: endorphin, serotonin, dopamine and oxytocin.


“When people talk about a ‘natural high,’ what they really mean is the body’s chemical response to something they’ve done,” he said. “And like everything else the body creates, those chemicals and how we respond to them are influenced by DNA.”


Almost every cell of the human body contains a nucleus that holds deoxyribonucleic acid, or DNA. Cells access the DNA, almost like going on a personal Intranet, to find instructions for how to behave, which proteins to create and even when to die.


“DNA influences traits such as our height, but that’s only part of the story,” Lessard said. “Our genes set a range of options. A host of other factors, including diet and environment, affect the final outcome, however. The same is true for happiness.”


A study of more than 2,500 Americans by a researcher in London turned up the 5-HTT gene, which affects the body’s flow of serotonin. Those with a longer version of the gene could release and process serotonin better than those with the short variant. The result: people with the one or two copies of the longer 5-HTT gene reported higher levels of general life satisfaction.


“I think genetics play a role in almost everything,” Lessard said. “That said, even if some genes create more or fewer of the chemicals needed for happiness, we still have a level of control. Some people are more genetically susceptible to diabetes or obesity, but they often can make choices that can impact how their genes respond.”


The same can be true for happiness, he said. Sociologists have found that the happiest people tend to be ones who sleep soundly, exercise, volunteer for causes about which they’re passionate and find meaning in their jobs.


“Our DNA might define our happiness spectrum, but the decisions we make determine where we fall in that spectrum,” Lessard said. “Long 5-HTT genes might just make the job a little easier.”