Humans spend a great deal of time trying to smell good. We wash, deodorise and perfume our bodies daily, suggesting body odour must matter. Yet scientifically, the picture is far less straightforward.

In the animal world, smell is a powerful communication tool. Many species use scent to signal readiness to mate, mark territory or warn of danger. Female moths, for example, release chemical cues that attract males over long distances in predictable ways.

Humans also produce body odour through sweat and sebaceous glands. In addition, apocrine sweat glands are concentrated in areas such as the armpits, genitals and around the nipples. These glands release oily secretions that skin bacteria break down into the characteristic smells associated with body odour.

Read more: The biology of body odour, from sweat glands to skin bacteria

Biologically, the human body is certainly equipped to produce odours that others can detect. Whether these odours carry information in the same way as scent signals do in other species remains uncertain.

Modern hygiene complicates the picture. In many societies, frequent washing and fragranced products mask natural odours. This makes it difficult to study how scent might operate in everyday human interaction under less controlled conditions.

Love stinks? Attraction, pheromones and genes

Smell is often assumed to play a major role in attraction. People frequently report liking a partner’s scent, and some studies suggest partners can recognise each other’s body odour. But the direction of the effect is difficult to untangle. Smell may help shape attraction, but emotional attachment and familiarity may also make a partner’s scent seem more pleasant.

The idea that smell shapes romantic attraction remains popular. Early studies suggested people might prefer the scent of partners with different immune system genes, potentially increasing the chances of healthier offspring.

Results, however, are mixed. Some studies support this pattern, others do not.........

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