EDMONTON, Alberta, Dec. 9 (UPI) -- There appears to be a link between fetal testosterone exposure and social behavior, such as aggression in adults, researchers in Canada say.
Peter Hurd, Kathryn Vaillancourt and Natalie Dinsdale of the University of Alberta looked at the gene that makes the body's testosterone detector, in an effort to determine whether variations in the detector's sensitivity to the hormone causes people to be more or less aggressive.
"In our samples, less sensitive genes indicated more aggressive behavior, perhaps because the bodies of those people wound up producing more testosterone to compensate," Hurd says in a statement.
Hurd says the findings can be likened to smoke detectors -- a less sensitive device requires more smoke in a room than a very sensitive one.
Testosterone levels and sensitivity are particularly important during fetal development, particularly since testosterone acts to influence fetal brain development indirectly, through a different receptor after it has been converted to a slightly different chemical, Hurd says.
"More or less prenatal testosterone seems to have consequences throughout a person's entire lifetime," Hurd says.
The varying levels of testosterone sensitivity or exposure seen in the study subjects are not related to extremely aggressive or criminal behavior. It's not as though these people were unable to physically control their emotions, it's much more subtle than that, Hurd says.
The findings are published in the journal Behavior Genetics.
