Ott said he learned not to pay attention to stepfathers, even one he had for years. “If I did something wrong and needed discipline, he was all over it. Otherwise, we didn’t have too much to do with each other.”

Meanwhile, Burgos’ sole significant male role model was a young man he saw a few hours each month courtesy of a Big Brothers program. His father had never been part of his life and his mother was a drug addict. He could count on his grandmother, but she died when he was 15, about the time his mentor moved away.

“I think there’s consensus that cultural and family factors are causing children’s family lives to be more unstable than in the past,” said Andrew J. Cherlin, author of The Marriage-Go-Round and director of the Hopkins Population Center at Johns Hopkins University. Experts debate whether recent cultural shifts or economic changes most undermine family stability, but, said Cherlin, “most who I respect believe both are at play.”

Most children weather family turmoil and wind up OK, said Cherlin, who coined the term “family churn” to describe what happens to families as couples split, often moving dad out of the home and a new man in. A study in the Journal of Marriage and Family said children in such homes experience an average of more than 5.25 partnership transitions. That’s tough for kids who are used to having their own fathers within reach.

“Dad also helps with impulse control and memory and enhances a child’s ability to respond effectively to new or ambiguous situations, for boys and girls,” said Warren Farrell, author of Father and Child Reunion. Children who are close to their fathers tend to achieve more academically, while kids with absent fathers are more likely to drop out. Fathers are the biggest factor in preventing drug use, Farrell said.

The time a dad spends with his children is a particularly strong predictor of how empathetic a child will become, according to commission of experts who wrote a proposal asking President Obama to create a White House Council on Boys and Men. The group, which Farrell helped assemble, compiled research showing infants with dads living at home were months ahead in personal and social development. Children who lack contact with fathers are more likely to be treated for emotional or behavioral problems. Girls with absent or indifferent fathers are more prone to hyperactivity. If dad is around, girls are less likely to become pregnant as teens.

As early as 1993, studies showed that dads also influenced whether their sons became teenage fathers. A Temple University study found no boys born to teen mothers became teen fathers if they had close relationships with their biological fathers, compared to 15 percent of those who didn’t have that closeness.

“None of this implies men are better as dads than women are as moms,” Farrell and the commission emphasized. Children need both.