“Some research has explicitly evaluated the effects of phenotypic similarity. DeBruine (2002) tested subjects in a two-stage trust game, where they had an opportunity to win larger rewards but also risked being cheated, if and only if they trusted their partner in the first stage. Computer morphing techniques were used to create different facial images of “partners” for 16 such two-stage games. For each subject, one-half of these facial morphs blended two stranger faces, but the other half blended the subject’s own face with a stranger’s. Subjects were significantly more likely to trust their self-morph partners. Controls ruled out differential attractiveness and familiarity as explanations for these results. Studies by Platek and colleagues (reviewed in later section) demonstrate an effect of phenotypic similarity on male investment decisions.” (David M. Buss, HoEP p. 487 in pdf)
Gives a hole new connotation to “trust thyself” eh? :D
