By using pairs of sisters who spent differing amounts of time living with their fathers, the study was able to control for inherited genes and environmental conditions, such as socioeconomic status or religious background, to isolate the effects of fathering quality on daughters.
"It's not enough for a dad to just be in the home," said Danielle DelPriore, a post-doctoral fellow in the University of Utah in the US and lead author of the study.
"The quality of a father's relationship with his daughter has implications for both the overall monitoring she receives from her parents as well as her likelihood of affiliating with more promiscuous or more pro-social friends," DelPriore said.
The study compared the outcomes of older and younger full biological sisters who experienced the divorce or separation of their parents while growing up, and thus spent differing amounts of time living with their fathers.
The study found that older sisters with greater exposure to their fathers were strongly influenced by the quality of fathering they received.
When fathering was high quality, parental monitoring was increased and older sisters were less likely to affiliate with sexually risky peers during adolescence compared to their younger sisters.
The opposite effects were found for older sisters who spent many years living with a low-quality father.
The researchers believe that in divorced/separated families, a father – and how he behaved – was likely to have exerted a stronger influence on an older daughter than a younger daughter since older daughters systematically received larger "doses" of dad's behaviour.
The results suggest a causal relationship between a father's behaviour and his daughters' experiences.
Different amounts of exposure to fathers of high or low quality changes daughters' social environments – the monitoring they received and the peers with whom they affiliated – in ways that can impact their sexual behaviour.
The findings suggest that the most effective programmes for reducing adolescent females' risky sexual behaviour might include components that both promote engagement with pro-social peers and aim to improve parenting skills, including parents' ability to effectively communicate with the teenagers.