Men more likely to initiate a kiss - and will lean to the right to do so
Humans are hard-wired to favour leaning to the right while kissing romantic partners, an international study has found.
The research, by the universities of Dhaka, Bath and Bath Spa, found that kiss recipients have a tendency to match their partners' head-leaning direction.
Experts built on work from western countries to investigate kissing behaviours in a non-western context, including a bias for turning the head to one side.
Their work, published in the journal 'Scientific Reports', studied 48 married couples in Bangladesh, where romantic kissing is not typically observed in public.
Couples were asked to kiss in their own homes, then go into different rooms and independently report back. Men were 15 times more likely to initiate kissing than women, and both partners showed a bias for turning their heads to the right.
Dr Rezaul Karim, from the University of Dhaka, said: "This is the first study to show sex differences in the initiation of kissing, with males more likely being the initiator, and also that the kiss initiators' head-turning direction tends to modulate the head-turning direction in the kiss recipients. Based on our prior work we are also able to make new hypotheses about the underlying neural basis for these behaviours."
The study found that more than two-thirds of kiss initiators and kiss recipients turned their heads to the right. Men accounted for 79pc of the kiss initiators.
A person being left or right handed predicted their head-leaning direction, but this was only the case if they initiated the kiss.