(AP) -- Politics may not be in the blood, but it could be in the genes. That's the theory a team of political scientists and geneticists is trying to prove with extensive studies of twins, genes and brain scans.
"I perfectly understand that some people are skeptical," said John R. Hibbing, a political science professor at the University of Nebraska-Lincoln who is involved in the research.
The idea goes back more than 2000 years, said John Alford, associate professor of political science at Rice University, who is working with Hibbing.
In 350 B.C., Aristotle wrote, "Man is by nature a political animal."
Now, Alford said, scientists are trying to improve on that.
Genetic researchers are trying to prove that social attitudes can be inherited, and have discovered strong correlations between the two.
So far, the political connection has relied on studies by Lindon Eaves, professor of human genetics and psychiatry at Virginia Commonwealth University. About 8,000 sets of identical and fraternal twins answered a series of questions on topics such as school prayer, nuclear power, women's liberation and the death penalty.
Identical twins, who share their entire genetic code, answered more similarly than fraternal twins, who are no more similar than non-twin siblings.
If you assume that both identical and fraternal twins share an environment, then the disparity between the results must be genetic, Hibbing and colleagues conclude.
Some scientists, however, are not ready to embrace the theory.
"The very idea that something like a political ideology could be heritable is incoherent," said Evan Charney, assistant professor of public policy and political science at Duke University. "It doesn't make any sense, and it's historically inaccurate."
Any similarities found in twins' political beliefs can be attributed to environment, not genetics, Charney said.
Charney's paper "Genes and Ideologies," written to argue many of Hibbing and Alford's claims, is being considered for publication by the Review of Politics, Charney said. He recently presented the work to the American Political Science Association.
"I have not proved that environment has caused this, but neither have they proved that genes have caused this," Charney said.
And environment, he said, is a far more plausible explanation.
Hibbing agrees his research isn't definitive.
"No specific (genes) have been connected to political traits," Hibbing said. "That is our group's main goal."
But social scientists typically dismiss genetic influence, and that's a mistake, he said.
The next step, Hibbing said, includes scans to observe the brain in action as subjects answer questions on political topics. That work is in progress at Baylor Medical Center in Houston, in collaboration with Rice University and Alford.
Next month, members of the team travel to Australia to work with Nick Martin, who is investigating the pattern of disease in families, including twins, at Queensland Institute for Medical Research in Brisbane. His research could provide important clues for Hibbing and Alford's hypothesis.
The goal is to persuade people to accept that political views aren't just random opinions thrown together by a combination of environmental influences.
"We can't just fall for the fairy tale that all people are genetically identical," Hibbing said. "Willful ignorance is unforgivable."
By ANNA JO BRATTON, Associated Press Writer
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