Positive Assortative Mating in Face Shape: Do Couples Tend to Look More Alike than Different?

BACKGROUND AND QUESTION 

Positive assortative mating, the tendency for individuals to choose mates that are more similar to themselves in phenotype than would be expected by chance, has been identified in humans for traits such as educational attainment, body mass index (BMI), dietary factors, and other physical measurements1,2,3. Facial phenotypic similarity between couples is another trait that has been observed across the world, and while there have been many scientific studies examining why this could be the case—reasons including implicit egotism, familiarity effect, and even game theory4,5,6—far fewer studies have aimed to quantitatively show that couples look similar to each other. This study aims to measure phenotypic facial similarity within couples through the use of 3D images acquired at Georgia Tech in The Facial Expression project.