THAT'S THE WHY:WHY DO we have a sense of smell? On the face of it, that sounds like a ludicrous question. To smell, of course! To sense when food is good or rotten, to enjoy the scent of flowers or to know whether those socks are fit for our feet or for the washing machine.

But maybe the functions of smell in daily life are not quite as plain as the nose on your face. A paper in PLoS Biology recently asked “ . . . how important is it for humans to have an intact sense of smell?”

The researchers, at the University of Dresden Medical School, sought some initial answers by studying 32 adults who were born without a sense of smell (they had a condition called isolated congenital anosmia, or ICA) and 36 age-matched controls who could smell.

Participants answered questions about their eating habits, household accidents, hygiene behaviours and relationships. They were also assessed for depressive symptoms.

So what did the study find? That people with ICA showed only slight differences in daily life functions related to olfaction, or smell.

“These differences are increased social insecurity, enhanced risk for depressive symptoms and enhanced risk for household accidents,” state the authors in the paper.

While such a small study is not going to provide definitive answers about why we have a sense of smell, it points to areas where more research could help, they argue.

“Although people who were never able to smell seem to cope well with this deficit, there are some restrictions, very worthy of further study,” they write.

“Likewise, the domains where we found no differences between people with and without a sense of smell are very interesting and raise further questions about the role of the sense of smell in daily life.”