The study investigated what effect wearing deodorant has on assessing masculinity and femininity. 130 female and male participants rated facial masculinity and femininity using photographs and a further 239 men and women rated odour samples of 40 opposite sex individuals.

The research confirmed that females appear to be, in some way, more sensitive or attentive to odour cues than males. All women who were wearing deodorant were rated as more feminine-smelling by men compared to when they had no deodorant on.

However, without deodorant men rated by women with high and low facial masculinity received significantly different ratings of odour masculinity- once a deodorant was applied these two groups of men became indistinguishable in terms of their rated levels of masculinity. Men who were low in face masculinity significantly increased their odour masculinity by applying a deodorant, but the highly masculine men showed no increase after deodorant application.

Dr. Caroline Allen, Psychology researcher at the University of Stirling, who led the study, said: "We're all aware that fragrances are often marketed as being feminine or masculine - take Old Spice for instance, who have recently parodied this with their hyper-masculine adverts, claiming that their product will allow you to smell like a super masculine guy.

"Our study found that when women apply a deodorant it does increase their rated body odour femininity, as would be expected. Though, it seems as though something else is at play when it comes to male body odour and male deodorants. Only those men who were rated low in masculinity to start with showed a significant increase after applying their deodorants, and the men who were highly masculine initially showed no increase after deodorant application.

"This means that men are able to use deodorant to artificially raise their game so to speak, levelling the playing field by making themselves comparable, at least as far as odour is concerned, to more masculine men. Our evolutionary preferences have likely shaped this difference in fragrance design: research findings show that we actually don't like high levels of masculinity which are often associated with aggressiveness and hostility, but we show no upper limit on our femininity preferences."