Human intelligence, fluctuating asymmetry and the peacock’s tail: General intelligence (g) as an honest signal of fitness

Assuming that general intelligence (g) is an honest signal of fitness, we expected g to be related to developmental quality as indexed by Fluctuating Asymmetry (i.e. non-pathological variation in the size of right and left body features). In a population sample of 44 men and 37 women, we assessed the relationship between Fluctuating Asymmetry (FA) and g, and, as a control, to the Big Five personality dimensions for which no theoretical relationship with FA was expected. We found a relation between g and FA in men and women, but only a marginally significant relation with Openness in women only. We conclude that about 20% of the variance in g is explained by FA, and discuss the implications for the evolution of g and human mate choice.