DETROIT -

While demonstrators weighed in on same-sex marriage outside Detroit federal court on Monday, the battle of expert witnesses continued inside.

Mark Regnerus is a sociologist from the University of Texas. He studied adults 18 to 39 who said their mothers or fathers had had a same-sex relationship.

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Regnerus says his study shows those adults were more likely to have been on public assistance, been unemployed, had an affair, smoke marijuana and had contact with the criminal justice system.

However, he made the comparison with people who spent their entire childhood with their biological mothers and fathers. Lawyers for the plaintiffs call his conclusions "apples to oranges." Regnerus did not make the comparison to people raised in unstable heterosexual homes.

Other researchers say there is no evidence that children raised by couples like April DeBoer and Jayne Rowse are less successful. Regnerus says those studies are too small and the people who took part are more whit and educated than the general population.

"We are definitely in the novel period of social science about same-sex relationhip ... Michigan should tread carefully," said Regnerus.

Judge Bernard Friedman must decide whether Michigan's ban on same-sex marriage violates the constitutional rights of same-sex couples.

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