As a society we believe that our political allegiance depends on which party best marries up with our needs and values—and that these are shaped by our life experiences. But research with twins suggests picking who to vote for in an election might have more to do with your genes than the policies of the parties.
At the Department of Twin Research, which hosts TwinsUK, the biggest adult twin registry in the U.K., we recently performed a poll of voting preferences. The twins were all born in the U.K. and were broadly representative of the U.K. population. The aim was to explore how much nature and nurture influence our party political allegiances and potential voting preferences so can we draw broader conclusions about people’s voting habits.
Twins provide a unique natural experiment for research. Identical twins share 100 percent of their genes, while nonidentical twins—like non-twin siblings—share about 50 percent. Both identical and nonidentical twins normally share the same environment while growing up. By comparing the differences and similarities between them we can identify how much of a quirk, disease, or trait is due to a genetic predisposition or environmental and cultural factors. Because twin studies adjust for culture and upbringing they are an ideal way to study political allegiances.
