Danny Wallace is demonstrating his male bonding technique; a light faux punch to my forearm, a casual shrug and a 'How you been then?'
The comedian, writer and radio presenter says, in mock seriousness: "When you meet up with a mate, that opening line is key. If you don't want to use that general opening line, you can also use a football result coupled with a theatrical rolling of the eyes to denote despair! It's usually despair over football results unless it's 'Whay-hey, they won' – and then it's OK to hug."
He warns that we all might be seeing more groups of men engaging in similar punching, eye-rolling and hugging rituals, because a scientific experiment, commissioned by Guinness and carried out by Oxford University psychologist, Robin Dunbar, has given them the official go-ahead to do so.
Its findings reveal that a night out, twice a week, with a group of up to five best mates, is the perfect boost for men's health and wellbeing. Chatting and laughing together boosts endorphins, the body's feel-good chemicals, and helps the immune system.
So, men who maintain social groups are clearly healthier, recover from illness quicker and tend to be more generous – yet two out of five men claim they only manage to meet their friends once a week, and a further third struggle to catch up even that frequently.
"Apparently, men don't find it easy to keep friendships going over phone and text, unlike women who are really good at that," says Wallace (37). "So science is telling males it's essential we get together in the flesh, otherwise friendships wither away.
"We have to obey science, this is a genius excuse for nights out. The next move must be to get this enshrined into law!"
In reality, Wallace admits he doesn't get a lot of time to hang out with his mates because his work dominates.
Born in Dundee, Scotland, he spent his childhood in Loughborough, Leicestershire and Bath, and was writing reviews for video games magazines at only 13 years old. At 22, he became one of BBC radio's youngest ever producers and was part of the team behind British Comedy Award-winning Dead Ringers. He was also creator and producer of Ross Noble Goes Global.
Wallace's latest novel, his tenth, will be published next year, and previous successes have included Are You Dave Gorman? and Yes Man. In the first, Wallace searched for men named Dave Gorman, with the comedian of the same name. It was a book, then a stage show and a BBC series.
In Yes Man, he carried out an experiment where he said 'Yes' to everything he was offered, with hilarious results. The concept was made into a film with star, Jim Carrey – and also changed Wallace's life. As part of it, he randomly agreed to buy a ticket for an Australian girl called Lizzie for Edinburgh Festival, which resulted in them meeting, falling in love and marrying, and they now have a four-year-old son, Elliot.
"I nearly lost Lizzie because while we were dating she was offered a dream job back in Australia. She took it, went home and I was heartbroken. But suddenly she contacted me to say 'I'm coming back for you', and that was it," he says with a beam.
"Fatherhood just gets better and better. Of course, I see my friends less – obviously not good for my health – and parenting is knackering.
"But you don't realise how much love your heart can hold until you have a kid."
Parenting's a rich source of comic material for Wallace, but he admits it has also made him not only more aware of his health, but also more anxious.
"Probably because I was an only child my mum was a bit more concerned than most that something would happen to me. Even into my thirties I'd get these calls in the middle of the night from her going, 'I had a weird dream about you – and all I'm saying is never go bungee jumping...' or whatever she'd dreamt about," he says with a fond smile.
"I used to just sigh, go 'OK', turn over and go back to sleep. Now I'm sympathetic. As a parent your whole landscape shifts."
Wallace professes to be an optimist. "Fundamentally, I follow three rules. I try to treat people as I'd want them to treat me; get involved in all sorts of things which helps make stuff happen, and then I endeavour to have fun, because surely that's the point of life.
"I think it's about constantly pushing yourself, rather like pushing a boulder over a hill – then the boulder will just roll down and by chasing after it, you never know where you'll end up."