Understanding Partner Preferences: The Role of Genetics in Assortative Mating

People tend to choose romantic partners who resemble themselves in various traits, a phenomenon known as assortative mating. This pattern has been observed in humans and across several species, including fish, which frequently demonstrate preference for similar mates. Recent research sheds light on whether this tendency is driven purely by personal choice or if underlying genetics play a significant role.

Assortative mating involves selecting partners based on physical, personality, or demographic similarities. Such preferences contribute to the genetic structure of populations, forming subgroups with shared traits. This behavior has gained increased attention on social media, exemplified by trends like the viral Siblings or Dating game, where participants guess whether two similar-looking individuals are related or a couple.

The hypothesis that genetics influence partner preferences is gaining scientific support. A forthcoming study in 4sychological Science5 by Kaitlyn Harper and Brendan Zietsch from the University of Queensland suggests that the connection between traits and preferences can be explained through inheritance. For instance, an individual who is tall may have inherited height from one parent and a preference for tall partners from the other. As a result, the genetic combination predisposes them to be both tall and attracted to tall individuals.

This concept, while grounded in evolutionary biology, is relatively novel in the context of psychology. Harper explains that using agent-based modeling, the researchers simulated populations over 100 generations, allowing them to observe how preferences and traits co-evolve. The models indicated that even with multiple preferences, genetic correlations naturally develop, leading individuals to select similar partners.

This approach highlights a parsimonious explanation for long-standing questions about partner similarity, and it extends beyond humans to animals, where traditional explanations might not suffice. The study underscores that assortative mating can emerge without active selection, simply through the inheritance of traits and preferences.

The findings open new avenues in understanding human and animal behavior, emphasizing the influence of genetics in social and mating choices. This interdisciplinary approach combines evolutionary biology and psychology, revealing how shared traits can be a byproduct of inherited preferences.

Source: https://medicalxpress.com/news/2025-08-partner-genetics.html