Many women today opt to raise kids alone, and these children become successful adults and occasionally, President of the United States. The trend toward single motherhood raises questions about the role a father plays in children’s development.

According to a new study by Canadian researchers, a father’s role in the growth and development of his children is very important. The research, which was done on mice, found that having an absent or non-participatory father produced physical changes in the brain that showed up as behavioral problems in adults.

“We used California mice which, like some human populations, are monogamous and raise their offspring together,“ said Gabriella Gobbi, senior author on the study, in a press release. “[So] although we used mice, the findings are extremely relevant to humans.”

Having an absent or non-participatory father produced physical changes in the brain that showed up as behavioral problems in adults.

The researchers compared the social behavior and brain anatomy of mice raised by both parents to those of mice raised only by their mothers. They found that mice raised without a father had abnormal social interactions and were more aggressive.

These effects were especially pronounced in female mice. Females raised without fathers also had a greater sensitivity to amphetamine, a stimulant.

These behavioral issues are consistent with those seen in human studies of children who grew up without a father. “These children have been shown to have an increased risk for deviant behavior and in particular, girls have been shown to be at risk for substance abuse,” Gobbi said.

The research uncovered defects in the prefrontal cortex of the paternally-deprived mice, an area of the brain that helps control social and cognitive functioning. The aggression and stimulant-sensitivity problems in the fatherless mice can be traced to these brain abnormalities.

The Research Institute of the McGill University Health Centre (MUHC) scientists hope their study motivates more scientists to investigate the role fathers play during critical stages of their children’s growth. The findings suggest that both parents are important in children's mental health development.

The study is published in the journal Cerebral Cortex.