PARIS - For people with anosmia, success does not have a sweet smell, nor does anything else.

Anosmia is the complete or partial loss of olfaction – or put another way, people with anosmia cannot smell anything. In everyday life, those who suffer from this disease are more often than others victims of domestic accidents, because they are not able to smell gas leaks; or the burnt smell that would have told them their house or building was going up in flames; or weren’t able to identify a dangerous product (ammonia, bleach, etc.) or spoiled food.

They are not able to appreciate food in all its dimensions, since – with taste – smell makes up a big part of the pleasures of the table. But in addition to pleasures of the table, there are those of the flesh.

The February issue of the journal Biological Psychology includes a German study that questions whether or not anosmia affects sexual life. The question may seem silly if we consider that humans have stopped smelling each other’s derrieres for a long time. But this is not to say that smell has no role in social relations – in fact this sense could be a means of communication, discrete or unsuspected, for Homosapiens.

“Less explorative”

The authors of this study recruited 32 people suffering from isolated congenital anosmia and 36 age-matched healthy controls. The subjects were given a focus questionnaire on daily events related to olfaction: meals, domestic accidents, personal hygiene, and sexual history. A second questionnaire tried to uncover signs of depression. Surprisingly, researchers found that anosmic men had five times fewer sexual partners than men with a full sense of smell.

The researchers found that anosmics were more socially awkward because of their handicap: they worry about their body odor, avoid eating with others, and have a hard time assessing others. Thus anosmic men “exhibit much less explorative sexual behavior,” according to the study. In other words, when they aren’t able to smell, men aren’t good at seeking out new partners – not because smells help them, but because not smelling makes them feel less secure.

With women, it’s totally different. Their number of sexual partners does not change, even if they cannot smell men. We know that the male body odor is normally an important factor in a woman’s choice of partner, because she uses it to detect clues about a man’s health. However, the study shows that for anosmic women living with a partner, they are much less secure about their partner than a “smelling” woman.

From an evolutionary point of view, it is precisely this security that a woman looks for in a man. Without smell, she cannot be sure she has made the right choice, the one with whom she will be willing to invest maternity and children’s education, in energy and time (first, nine months, then twenty-five). And she will never know when he reeks of alcohol -- or carrys the whiff of another woman's perfume.