For a long time advocates claimed divorce had no permanent effect on children. Now we're acknowledging this isn't so. We shouldn't dismiss warning signs accompanying redefining marriage:

My friend Judy Wallerstein, who died last month at age 90, liked to tell the story of how she was drawn into the rancorous national debate on divorce. It was 1970 and Judy, a psychologist, had just moved with her husband and three children from the Menninger Clinic in Topeka, Kan., to Marin County in northern California.
... Judy went to the Berkeley library to see what had been written about how children react to divorce. And found nothing.

Given her initial idea that divorce may not be so bad, it's ironic that Judy became best known as one of the nation's leading critics of divorce. The heart of her findings:

• The effects of divorce on children are not transient. They are long-lasting and profound, persisting well into adulthood.
• The quality of the post-divorce family is critical. Parents are told "don't fight" but the issue is much bigger. Beyond custody and visiting plans, children need to be fully supported as they grow up. Few are.
• Age matters. Little ones, ages 2 to 6, are terrified of abandonment. Elementary-school-age children, 7 to 11, grow resentful when deprived of opportunities they would have had if their parents had stayed together. Preadolescents, ages 11 and 12, can be seduced by what Judy called "the voices of the street." Many teenagers, taking on the role of parent, become overburdened.
• Stepfamilies are laden with land mines that no one sees coming.

Second Chances was a best-seller, but reaction to Judy's findings was harsh. Parents did not want to believe it. Rival academics attacked her. Through it all, she stood up to her critics. -- Slate