New research published in human nature report that parents do not simply invest more in their daughters and sons overall, but rather that investment varies by sector, with mothers, fathers, daughters, and sons showing distinct patterns.
Human parenting is unique in the animal kingdom. This is because human child rearing is long-term, expensive, and often requires a great deal of care from both mother and father. Much of the previous research on parental investment has focused on broad questions such as how much time and money parents spend on their children, rather than examining the different ways parents invest in their offspring. But raising a human child involves more than just food, protection, and money. Parents also teach skills, provide emotional support, guide social behavior, form moral values, encourage education, and provide advice about relationships and adult life.
Sid Dougan and colleagues investigated whether these different forms of parental investment differed by both parent gender and child gender. Their research was motivated by an evolutionary framework that suggests that parents may invest differently in daughters and sons if their children have historically faced different adaptive challenges.
For example, daughters may receive more guidance in relationships and protection, while sons may receive more encouragement in athletics, competitions, practical skills, etc. The researchers also expected that mothers and fathers would differ in areas where their own experiences and gender-related roles may have shaped different forms of parental expertise.
The researchers analyzed data from 105 adults, 49.5% of whom were women, originally collected as part of a longitudinal study of newlywed heterosexual couples. These couples were first recruited through public records of marriage licenses issued in Washtenaw County, Michigan, USA in 1989. The current analysis used data collected at time point 2, when participants were in their third year of marriage. Participants’ ages ranged from 19 to 36 years, with a mean age of 26 years. Most are reported to be white and most grew up in suburban areas of the United States.
Participants completed a 105-item questionnaire regarding parental behavior they experienced while growing up. For each item, they rated separately the extent to which the behavior was performed by the biological mother and biological father, using a scale from 0, meaning “not at all,” to 7, meaning “quite a bit.” The authors then organized parental behavior into conceptually distinct domains.
After removing items that were too vague or overlapped between categories, the final measure included 73 behaviors grouped into 13 areas: mating and relationship guidance, athletics and physical training, mechanical and practical skills, social and moral guidance, encouragement of competition, sexual tolerance, direct care and domestic assistance, bonding and emotional support, educational and career support, protection, discipline and regulation, wisdom and life guidance, and provision of material goods.
Overall, mothers provided more parental investment than fathers on average across all domains, but this difference was particularly pronounced for daughters. Daughters received more investment in mating and relationship guidance, protection, and material provision than sons. Sons received more investment in athletics, physical training, competitive encouragement, and sexual permissiveness than daughters. In other words, the findings do not suggest a simple pattern in which one gender receives more parental investment overall. Instead, daughters and sons seemed to receive different types of investments.
The results also showed clear differences between mothers and fathers. Mothers invested more than fathers in direct care and domestic support, bonding and emotional support, social and moral guidance, discipline and regulation, marital and relationship guidance, wisdom and life guidance. Fathers have invested more in exercise, physical training, mechanical and practical skills than mothers.
In some domains, there were no significant gender differences, including education and career support, where mothers and fathers invested similarly and daughters and sons received similar levels of support.
Some interactions also occurred. Mothers showed a stronger daughter-focused pattern in mating and relationship guidance, while fathers showed a stronger son-focused pattern in athletics, physical training, and mechanical and practical skills.
The authors noted that the sample was relatively small and drawn from a Western educated, industrialized, rich, and democratic background (WEIRD), which limits how confidently the findings can be generalized across cultures.
The study, “Gender Bias in Parental Investment Patterns,” was authored by F. Sid Dougan, William Costello, and David M. Bass.
