Conducted by sociologist Hiromi Ono, the study measured the amount of time parents spent with their young children.
It was found that children spent comparable amounts of time with their biological mothers regardless of the family structure in which the children were living (i.e., dual-parent homes that included their biological father, a stepfather or their mother's live-in partner).
After analysing the time allocation of a variety of male parental figures (including biological fathers, stepfathers and unmarried male partners), Ono found that married stepfathers were less involved with their stepchildren than biological fathers were with their own children.
On the other hand, kids living with their biological mother and her unmarried male partner spent similar amounts of time with this father figure as children from traditional families spent with their biological fathers.
"Children have no control over their family situation, so it's encouraging to find that the amount of quality time that they have with their parents is largely unaffected by their family arrangement," said Ono.
Ono found that if a mother disagreed with the practice of cohabitation before marriage, her children tended to spend less time-approximately 4.6 fewer hours per week-with their previously married stepfather.
But she did not encounter any difference in paternal involvement levels for children with mothers who strongly supported pre-marital cohabitation.
The results of the study revealed that children spent about five hours more with a biological mother than with their male parental figure (biological father or otherwise) per week. Girls spent more time with their mothers than boys did, but boys spent more time with their fathers.
When biological mothers worked longer hours, children spent less time with their mothers, yet when fathers worked longer hours, children spent more time with them.
Ono limited her study to two-parent families with children between six and 12 years old living with their biological mothers. The study used time diary data from the Child Development Supplement of the Panel Study of Income Dynamics from 1997 and 2003.
The study will be presented at the annual meeting of the American Sociological Association.