As the Republican National Convention gets under way in Florida with Mitt Romney formally accepting his party's presidential nomination, a new study suggests genes may play a role in people's political views. Researchers say genetic influences seem to be especially strong as related to social issues.

For years, political scientists assumed that people's political views were determined by their environments, such as what their parents and friends believed, and the communities in which they lived.

But a new study suggests that environmental factors are not the only determinant and that genetics influence roughly half of a person's political beliefs.

Rose McDermott, a professor of political science at Brown University in Rhode Island, co-authored the latest study. She said societal factors, such as family and friends, can shape people's political affiliations but that biology seems to influence their views in general.

“The underlying liberal to conservative tendency seems to be the piece that’s informed by these genetic factors,” said McDermott.

The research is based on analysis of data from dozens of twin studies in the United States and Australia. Identical twins have the same DNA and, McDermott says, are 60 percent more likely to hold similar political beliefs, suggesting a strong genetic role in political traits. Non-identical, or fraternal twins, who are genetically different, are more likely to have differing political beliefs, suggesting a stronger environmental role in political preferences.

Because of the newness of the research, experts have only identified a few genes that may influence behavior such as voter turnout and political violence.

But genetically-inherited political beliefs, according to McDermott, seem to play out most strongly in forming opinions on social issues.

“We had to take care of our children for many, many, many generations. And so in a modern day context, that could play as attitudes toward abortion, gay marriage and those sort of things,” said McDermott.

McDermott and her colleagues hope their findings may lead to deeper insights about political ideology, and its impact on public policy.

An article on genetic influences on political views appears in the journal Trends in Genetics.