Humans are probably the only species in which parents try to influence who their children mate with

Parental Influence and Sexual Selection. Menelaos Apostolou. June 2021. https://www.researchgate.net/publication/352710406

Abstract: This chapter addresses how the genetic relatedness between parents and their children results in the two parties having converging as well as diverging interests. In the domain of mating, these interests, along with other factors such as the trade-offs inherent in mating, give rise to an opportunity cost of free mate choice: Parents have much to lose if they allow their children to exercise choice freely. This opportunity cost provides a strong incentive to parents to influence their children's mate choices. In preindustrial societies, parents manage to exercise direct control, which is predominantly manifested in the institution of arranged marriage. In postindustrial societies, parents exercise influence indirectly through manipulation. Ultimately, parental influence over mating gives rise to a sexual selection force, namely parental choice, which may be unique to the human species.

Sexual Selection Under Parental Choice—Implications

Sexual selection under parental choice does not constitute a theoretical possibility, but an actual phenomenon: The ethnographic and historical records make a clear case that, in the preindustrial context, mating is typically regulated by parents who are driven by well-defined preferences and who choose spouses for their children accordingly. It follows that genes that code for traits which make individuals more likely to be selected as in-laws have a greater likelihood of being represented in future generations than alternative genes. Parental choice has only recently been proposed as a sexual selection force (Apostolou, 2007), and so far specific adaptation shaped by parental choice has not yet been identified. Even so, the effects of parental choice can be observed indirectly.

In particular, as discussed earlier, there are good reasons to believe that, until the onset of the Industrial Revolution and the transition to postindustrialism, parents exercised considerable influence over their children’s mating decisions. Accordingly, many adaptations involved in mating have been shaped by parental choice. The transition from preindustrial to a postindustrial context has severely weakened parental choice and strengthened individual mate choice, as people in the latter are generally free to choose their own partners. However, as the transition to postindustrialism has occurred very recently, there has not been sufficient time for selection forces to adjust adaptations to work effectively in the contemporary context. That is to say, people carry adaptations which may have enabled them to be selected as in-laws by parents, but which may not be equally effective in enabling them to be selected as partners by their children. In addition, they may lack adaptions which are required to be effective in a contemporary mating market.

For instance, in an arranged marriage context, people do not need to actively flirt with prospective partners, which means that selection pressures on developing good flirting capacity were weak in the ancestral context. In consequence, many people today may lack good flirting skills, which are important in contemporary postindustrial societies in which people have to find mates on their own. Recent studies have found that poor flirting skills are one of the most frequently reported reasons for being single (Apostolou, 2017b, 2019).

Accordingly, due to mismatch between ancestral conditions, where parents dominated mate choice, and modern ones, where they do not, it could be predicted that a considerable proportion of people living in postindustrial societies would experience difficulties in attracting mates. Consistent with this prediction, recent studies have found that about one in two people experience poor performance in the domain of mating (Apostolou et al., 2018). As a consequence of such poor performance, a considerable proportion of individuals are involuntary single: They want to be in a relationship, but they face difficulties in doing so. One recent study found that about one in four in the Greek cultural context are involuntarily single as are more than one in five in the Chinese context (Apostolou & Wang, 2019).

Overall, developing a more accurate understanding of how sexual selection works in our species could enable us to better understand phenomena such as poor mating performance and involuntary singlehood. Such an endeavor requires acknowledging parental choice as a sexual selection force and taking into consideration the ancestral human condition. It requires also a more thorough understanding of parental choice, which could be achieved by augmenting our understanding of in-law preferences as well as by identifying specific adaptations been shaped by parental choice.