Donald Trump and Emmanuel Macron sparked something of an online frenzy recently when it became clear just how close the two presidents had become by how mutually tactile they were. North Korean leader Kim Jong-un and South Korea's Moon Jae-in sparked a similar reaction when they made history by joining hands to cross the world's most heavily armed border for talks on denuclearisation.
The Franco-American special relationship saw Mr Trump and Mr Macron holding hands and hugging and kissing while the US president even fondly brushed dandruff off the French leader’s shoulder.
Some media reports used the portmanteau “bromance” to describe the interaction. But what are the unwritten social rules of male-to-male physical contact? And when did male leaders become so unexpectedly tactile?
Where I grew up in the north of England, physical contact between male acquaintances tended to be restricted to the briefest of handshakes. The only excuse for more intense physical contact was if someone scored a goal.
Coming from such a background presented a challenge during my early days in the UAE. For example, when I would stand in line queuing for some service or other, it would disturb me that I could feel the breath of the man behind me on the back of my neck.
The first time I travelled outside Europe was to Morocco. The sights, sounds and smells of Tangiers beguiled me.
One sight that struck me as unusual, however, was the groups of young men leisurely walking through the streets hand-in-hand. Sometimes it was just a couple of men but at other times the affectionate hand-holding could extend to four, five, even six participants. I was in completely new territory.
Today as a long-term resident of the UAE, a beautifully multicultural society, I am used to seeing men holding hands. I've even seen men interlocking fingers and swinging their arms in unison like playful children.
Such practices are not that uncommon among some of the UAE’s residents. Men kissing men is pretty standard, as is touching cheeks, foreheads and rubbing noses.
Anthropologists might discuss my peculiarly British reserve with reference to proxemics, a theory about how humans use physical space.
Proxemics looks at things like how close we typically stand to one another, how much physical contact we use and what actions we take if someone violates our personal space.
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Proxemics suggests that interpersonal space preferences and behaviours are picked up by observing other people around us.
For this reason, interpersonal distance and levels of physical contact can vary significantly across different cultural groups.
The anthropologist and father of proxemics, Edward Hall, split the world into two neat groups, which he termed contact and non-contact cultures.
A study published last year in the Journal of Cross-Cultural Psychology looked at interpersonal distance preferences across 42 countries.
The study examined three levels of interpersonal distance: social distance (strangers), personal distance (acquaintances) and intimate distances (family, friends and loved ones).
Surprisingly, one of the study’s primary findings was related to climate. People in relatively colder countries generally preferred greater social distance when interacting with strangers but less distance when dealing with family, friends and loved ones.
Another study undertaken within the US also supports this finding, with participants from warmer states showing closer contact behaviour and being more tactile than their counterparts in colder parts of the country. Could this mean warmer lands equal warmer people?
In a country like the UAE, where people are from a variety of cultural and climatic backgrounds, proxemic rules are occasionally going to get broken.
If your work colleague stares too intensely, speaks too softly, stands too close or holds onto your hand for too long, it is not necessarily an intentional invasion of personal space.
And while we might feel some minor discomfort in such situations, it is worth remembering that human contact, especially touch, is an excellent promoter of wellbeing.
The right kind of touch can lower one's heart rate, blood pressure and reduce the levels of cortisol, the stress hormone. It can also stimulate the release of hormones and neuropeptides associated with positive emotions.
Perhaps the French and US presidents’ proximity and tactility were a form of self-care, with both men aiming to reduce stress and promote wellbeing while simultaneously pursuing their national interests.
Dr Justin Thomas is an associate professor at Zayed University
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