London: Our nose is central to the way we form relationships and a good sense of smell is vital for a long-term commitment, according to new research on sensory systems.

The simple answer to the question of whether any relationship is "the one" seems to be that your ideal man or woman gets up your nose, scientists say.

In a new study, reported in the journal Biological Psychology, researchers looked for the first time at the effect of being born without a sense on smell on men and women's relationships, The Independent reported.

The research involved analysing data on men and women aged 18 to 46 with no sense of smell and comparing it with information from a healthy control group.

The results showed that men and women who were unable to smell had higher levels of social insecurity.

In men, but not in women, it led to fewer relationships. The men with a faulty sense of smell averaged two partners compared with 10 for healthy men.

One theory is that the lack of a sense of smell may make men less adventurous. They may have more problems assessing and communicating with other people.

The two groups of women had the same average number of sexual partners four. But the women who couldn't smell well lacked confidence in their partners: they were around 20 per cent less secure in their relationship.

Lacking a sense of smell had no impact on their relationships with close friends, suggesting that smell plays a role for women specifically when it comes to their

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