Anyone who has travelled on a crowded subway train will have experienced the remarkable range of odours that the human body can generate, but it is debatable whether these are likely to lure us to our perfect partner. The search for chemical cues involved in human sexual selection has been hampered by the fact that our 'natural' scent is obscured by many factors, from the soap we use to the food we eat. However, Martha McClintock from the University of Chicago believes that women can still sniff out subtle differences in male body odour that reflect variation at the major histocompatibility complex (MHC).

The New York Times (22 January) describes the rationale behind her latest experiment: “men were told to avoid distracting odours like ... spicy foods, deodorants, pets or sexual activity. Their T-shirts, worn for two days, were then placed in boxes where they could be smelled but not seen. The women were asked which box they would choose 'if they had to smell it all the time'”.

The women tended to prefer the scent of a man whose MHC genes resembled those of her father, but not her mother, prompting headlines such as “Women want a man who smells like dad” (Independent UK, 21 January). The evolutionary implications are unclear, but one possibility is that “children inherit a tried and tested immune system while leaving room for new protective influences” (The Mirror, UK, 21 January).

Not everyone was convinced. Behaviourist Wayne Potts points out that “mice seek high MHC similarity in communal nest neighbours but low similarity in their sexual mates” (Indianapolis Star, 7 February). More worryingly, “asked what the scent reminded them of, many [women] said 'K-Mart' [a US supermarket chain], presumably because of the boxes' packaging” (New York Times).