By LAURIE TARKAN

It used to irk Melissa Calapini when her 3-year-old daughter, Haley, hung around her father while he fixed his cars. Ms. Calapini thought there were more enriching things the little girl could be doing with her time.

But since the couple attended a parenting course - to save their relationship, which had become overwhelmed by arguments about rearing their children - Ms. Calapini has had a change of heart. Now she encourages the father- daughter car talk.

“Daddy’s bonding time with his girls is working on cars,” said Ms. Calapini, of Olivehurst, California. “He has his own way of communicating with them, and that’s O.K.”

As much as mothers want their partners to be involved with their children, experts say they often unintentionally discourage men from doing so. Because mothering is their realm, some women expect fathers to do things their way, said Marsha Kline Pruett, a professor at the Smith College School for Social Work and a co-author of “Partnership Parenting” with her husband, the child psychiatrist Dr. Kyle Pruett .

Yet a mother’s support of the father turns out to be a critical factor in his involvement with their children, experts say - even when a couple is divorced.

Uninvolved fathers have long been accused of lacking motivation. But research shows many societal obstacles work against them. Even as more fathers change diapers or drop children off at school, they are often pushed aside in ways large and small.

“The walls in family resource centers are pink, there are women’s magazines in the waiting room, the mother’s name is on the files, and the home visitor asks for the mother if the father answers the door,” said Philip A. Cowan, an emeritus professor of psychology at the University of California, Berkeley, who along with his wife, Carolyn Pape Cowan, has conducted decades of research on families. “It’s like fathers are not there.”

In recent years, several fathers’ rights organizations have offered father-only parenting programs and groups, and studies have shown that these help men become more responsive and engaged with their children.

But a new study by the Pruetts and the Cowans found that the families did even better if mothers were brought into the picture. Low-income couples were randomly placed into a fathermother group, a father-only group and a control group of couples. The controls were given one information session; the other two groups met for 16 weeks at family resource centers, discussing parental issues.

In both of those groups, the fathers not only spent more time with their children than the controls did, but were also more active in the daily tasks of child-rearing. They became more emotionally involved with their children, and the children were much less aggressive, hyperactive, depressed or socially withdrawn than children of fathers in the control group.

But notably, the families in the couples group did best. They had less parental stress and more marital happiness than the other parents, suggesting that the critical difference was not greater involvement by fathers in child-rearing but greater emotional support between couples. “The study emphasizes the importance of couples’ figuring parenting out together and accepting the different ways of parenting,” Dr. Kline Pruett said.

New studies support a greater appreciation for the way fathers approach parenting. / BRIAN WAGNER/GETTY IMAGES