If eyes are the windows to the soul, smell is the doorway. Swiss researchers recently reported that male body odour has a strong bearing on the choice of mates by females. The unusual study involved sniffmg of male T -shirts by female volunteers, who rated shirts for pleasantness and sexiness ( Scientific American, VoI273,No5).

Researchers established that females rated as more alluring the smells from shirts that were worn by men whose major histocompatibility complexes (MHCs), a crucial part of the immune system, differed the most from their own. However, females on the contaceptive pill preferred males of similar MHCs.