While women exposed to HEX consistently went for the loudest and most unpleasant noises, men who were exposed to HEX consistently chose milder noises than their non-HEX-exposed counterparts.

“Male aggression translates many times into aggression toward newborns; infanticide is a very real phenomenon in the animal kingdom.

“HEX, it would seem, affects men in that there was more social regulation, their aggression was kept in check and it served as a ‘cool down’ signal for them, while in women the regulation decreased and it can be thought of as a ‘set free’ signal.”

In addition to the finding that the scent of HEX affects men differently than it does women, the study is “among the first” to demonstrate a direct link between a molecule’s smell and human behavior.