Republican delegates gathered in Tampa for the GOP convention have a lot in common: An inclination to be politically involved. A distaste for taxes. A belief that it’s time for a change in Washington.

And, perhaps, key stretches of DNA, according to a new study that examines the links between genetics and political beliefs.

“Genetic influences account for a substantial proportion of individual differences in political traits,” wrote political science professors Peter K. Hatemi of Penn State University and Rose McDermott of Brown University in an article published Monday in the journal Trends in Genetics.

To reach this conclusion, Hatemi and McDermott examined studies of identical and fraternal twins, an approach that allows experts to determine the degree to which a given trait is determined by genes and how much can be chalked up to environmental influence. They also reviewed studies of extended families as well as work that attempted to correlate mutations in individual genes with particular political traits.


The papers Hatemi and McDermott assembled examined a range of characteristics, including levels of political participation, liberal versus conservative ideology and attitudes about race, sex, religion and the military. Thousands of genetic variables seem to play a role in molding political identity and behavior, the researchers wrote.

There were limits to biology’s influence. Twin studies showed that until young adults leave the nest and escape the “powerful social pressures” of their parents’ home, the genetic influences on their politics aren’t apparent. And while some research has identified “candidate genes” that may be associated with certain political behaviors — a gene called 5-HTT, which has a role in regulating serotonin, has been implicated in voter turnout, for example — scientists have yet to identify a specific gene that influences whether someone is a Republican or a Democrat, an activist or apathetic.

“There is not a gene for liberalism or any political trait,” the co-authors wrote.

But they took issue with critics who dismiss outright the notion that genes might have an influence on politics — which, they noted, can be viewed as an extension of the same interpersonal traits that have governed human survival since ancient times.


“Modern questions about immigration are similar to the primal need to recognize and deal with out-groups,” they wrote. Attitudes about welfare reflect age-old questions about sharing resources, while views on foreign policy are the modern-day equivalent of concerns about protecting one’s tribe.

Studying how genes influence politics “has real implications for the reduction of discrimination, foreign policy, public health, attitude change and many other political issues,” Hatemi, who is currently at the University of Sydney in Australia, said in a statement.

eryn.brown@latimes.com