Odor in Human Mate Choice

A person chooses a mate with advantageous genes through odor and facial symmetry. Dustin J. Penn and Wayne K. Potts discovered that mice are capable of smelling the potential mates’ major histocompatibility complex (MHC) through the scent of urine. Penn and Potts found that the mice preferred the scent of mates with a dissimilar MHC genotype to their own. Claus Wedekind investigated an odor mediated mating system in the human species through his “sweaty t-shirt study.” He found, similarly to the results of Penn and Potts, that women rated males’ scent as more pleasant and sexy when their MHC was dissimilar to their own. Contrastingly, women on contraceptives preferred the scent of MHC similar males. To address contraception as a confounding factor, S. Craig Roberts completed a similar study, finding a trend of decreasing preference for dissimilar MHC among the pill-using group, and an increasing preference for dissimilar MHC among the non-pill-using group. If women can smell and prefer facial symmetry (FA), are MHC and FA preference correlated? Randy Thornhill investigated this study. He found neither FA or facial attractiveness predicted MHC dissimilarity, MHC heterozygosity, or commonness of MHC alleles to the opposite sex. Since Roberts contradicted Wedekind, and Thornhill partially supported both Roberts and Wedekind, it is important to count on future studies to support or reject claims relating to preference for similar or dissimilar MHC and FA.