Men and women report more conflict with their mothers-in-law than mothers, study finds
A recent study published in the journal Evolutionary Psychological Science examined the cooperative and conflictual aspects of affinal relationships (i.e. relationships with in-laws). The results revealed that men and women report more conflicts with their mothers-in-law than mothers, and mothers report more conflicts with their daughters-in-law than daughters.
Forming lasting relationships with parents of long-time partners facilitates bonding and investment in offspring by both sexes. Despite the many benefits of affinal relationships, conflict is also a central feature. Hamilton’s rule helps explain why biological parents are invested in each other’s survival, which can also be seen in animals. For example, older female squirrels sometimes signal the presence of predators, revealing their location and sacrificing their own lives, in order to warn their biological parents. Although mothers and fathers are not related in most societies, they cooperate and have a common interest in the survival of their children, which creates an interdependence between two families. Since affines (i.e. parents by marriage) have shared genes with only one parent, their interests will generally align with that parent.
Jessica D. Ayers and colleagues write, “It leads affines to experience similar types of conflict as unrelated relatives and can motivate behaviors that further their genetic kin’s interest, even at the expense of their affines. The affinal conflict can therefore be considered as an extension of the genetic conflict between mothers and fathers.
Given the shorter birth interval of human females compared to non-human apes, females face the challenge of caring for multiple offspring at the same time and benefit from having positive affinal relationships. Ancestral women may have relied on the help of biological relatives for childcare; however, this would not be possible if the genetic parents were not geographically close. This would have required the support of affinal relationships in child care. And because the allies have a genetic interest in the offspring, it would incentivize them to provide the same quality of childcare as the mother’s genetic parents.
While female affinal cooperation focuses on caring for family and maintaining social ties, male affinal cooperation is concerned with establishing and maintaining social relationships, acquiring a mate, protecting self and others and the investment of resources in children.
Mothers and daughters-in-law tend to have differing interests when it comes to fitness, which can lead to conflict. “For example, a mother-in-law’s son/daughter-in-law’s partner’s resources are limited, so the daughters-in-law prefer her husband to allocate resources to her and her family, while the -mother prefers her son to allocate resources. resources to other family members.
Conflicts tend to exist in the same areas as cooperation, including child custody, material resources for loved ones, and time spent with children. Conflicts in these areas could lead to the acquisition of other social relationships, which could become a later source of conflict. For example, “Child custody disputes can reduce the quality of the relationship between mother and daughter-in-law, causing the daughter-in-law to seek out additional social relationships to help with child custody, which can aggravate his relationship with his mother-in-law”. -straight.”
Mate acquisition and retention, as well as self-protection could also be sources of conflict in affinal relationships, since these interfere with the fitness interests of mother and daughter-in-law.
In this study, Ayers and colleagues examined cooperation and conflict between in-laws. A total of 308 participants were recruited from online platforms. Participants answered demographic questions (e.g., age, gender, education, marital status) and provided the names/initials of their affinal and genetic parents that would appear later in the study. Participants answered many questions about these relationships, such as the duration and overall levels of cooperation and conflict in various domains (eg, resources, social relations, security). The researchers derived a “conflict ratio in interactions” metric to assess whether these relationships were primarily characterized by conflict or cooperation.
The results suggest differences in perceptions of conflict with genetic and affinal parents. Both men and women reported more conflict with their mothers-in-law than mothers, and mothers reported more conflict with their daughters-in-law than their daughters.
Additionally, fathers reported more conflict with their daughters than their daughters-in-law. It could be that these conflicts center on the choice of a partner and the addition of a new affiliative relationship in a father’s coalition network. If a father thinks his step-son would strengthen the coalition, one would expect that conflict to lessen over time.
The areas in which participants reported the most conflict included material resources and family care, both of which are critical to long-term reproductive success.
A limitation to the current work is that participants had to have relationships with living genetic and affinal mothers to be included in the analyses. This would have excluded participants who were involved in high-conflict relationships that ended up introducing a bias in the results in favor of cooperation.
The study, “Mother-in-Law Daughter-in-Law Conflict: an Evolutionary Perspective and Report of Empirical Data from the USA,” was authored by Jessica D. Ayers, Jaimie Arona Krems, Nicole Hess, and Athena Aktipis.