Men born without a sense of smell report having significantly fewer sexual partners compared to other men, and women affected with the same disorder report being more insecure in their relationships, according to new research.

While the researchers are unsure as to how smell can affect romantic relationships, they suspect that people with anosmia, or no sense of smell, are insecure because they have missed numerous emotional signals all their life.

"A lot of social signals are transported through the olfactory channel, and they are probably missing them," said researcher Ilona Croy, a psychologist at the University of Gothenburg in Sweden, according to LiveScience.

The latest findings were published in the journal Biological Psychology.

The Anosmia Foundation estimates that 2 million to 5 million American adults have taste and smell disorders. While some people are born anosmiacs, others lose their ability to smell because of head trauma, nasal growths, radiation cancer treatment or diseases like Alzheimer's.

Past research suggests than humans subconsciously transmit emotions through smell. Previous studies revealed that the smell of fear is contagious, that humans can differentiate between odors of nervous sweat and exercise sweat, as well as be influenced by odor signals when choosing a mate.

In an earlier study published in the journal PLOS ONE, Croy and her team found that people born without an olfactory bulb, the region of the brain responsible for smell, were more socially insecure and were more likely to be depressed compared to those born with an intact sense of smell.

Croy and her team decided to analyze whether there was a difference in the effect of smell between genders.

They found that while men who had the ability to smell reported having on average nine sexual partners over their lifetime, men who couldn't smell reported only having three.

While anosmic women did not report a difference in the number of lifetime partners compared to women who had the ability to smell, anosmic women reported being more insecure about their partners than other women.

Researchers explained that anosmiacs could feel more socially awkward because they have missed many social signals transmitted by the nose. Therefore, as a result, many men with the condition may not be confident enough to seek new partners.

"The men may have less exploratory behavior; they are not walking around like, 'Hey, I am the man!'" Croy wrote in an email to LiveScience.

Croy explained that for women, this social anxiety could translate into them being more insecure about their romantic relationships.