Warning: the truth behind handshake-sniffing may bum you out

This is a summary of an amusing and very interesting article that originally appeared in The Guardian on Monday, 9th March.

As we all know, a firm handshake is important in making a good first impression. It’s a sure sign of physical strength and, rightly or wrongly, we use it to make all manner of judgments about character, personality and sincerity.

New research now suggests that we take away much more than this – quite literally – because shaking hands may also be a way that we smell each other. An Israeli team has published a paper that shows handshakes transfer aromatic compounds thought to be involved in social assessment – that is, making judgments about someone else by virtue of how they smell.

The researchers analysed the chemical compounds present on clean surgical gloves and those that had been worn during a single handshake with the bare hands of 10 volunteers. A range of chemical compounds were transferred, including some involved in animal interactions or already known to occur in human skin secretions.

So handshakes transfer smelly compounds. And how often we smell our hands following a handshake depends on who we greet. By secretly filming 150 participants, the researchers found that both men and women spent more time smelling the hand they used in the handshake when they greeted someone of the same gender. When they greeted a member of the opposite sex, they spent more time smelling their non-shaking hand.

So what exactly might we be assessing when we check out hand odour, and what might we use that information for?

Smell is usually thought to be important in sex and attraction, so it was surprising that sniffing of the shaking hand increased the most after greeting someone of the same sex. The researchers suggested that this could be a way to assess the competition (though they admit they did not ask about sexual orientation of the participants).

That would not rule out using hands to sniff out potential partners. Reactions to smells can change depending on context, so perhaps people increase focus on the opposite sex in more socially relevant settings, or if they are single and searching for someone special.

But because hands wander, they pick up these more intimate odours and make them accessible in a socially acceptable way. In other words, offering a handshake could just be a polite and modern version of inviting someone to “sniff my butt”.

Read the full article here.