Tell anyone that you’re off to a North London venue for a couple of hours of “adult fun” and the immediate response is raised eyebrows and maybe a leering wink. But this is definitely a knickers-on experience. I’m going to play cowboys and Indians (or should that be Native Americans?).

It’s 7pm and nearly everyone has arrived straight from work. Some of the men are still in office shirts and the women have kicked off their heels; preferring bare feet. We have all come to indulge in a bit of horseplay in a training centre, in Finchley. We are a mixed bag of playmates – IT specialists, teachers, property developers and students; singles, couples, men, women, different social backgrounds and ages – all prepared to be downright silly.

But there’s no embarrassment in pretending we’re 6 again, says Cary Cooper, professor of organisational psychology and health at Lancaster University, in fact it’s healthy. “Releasing our inner child is very good for us, as we lose the ability to have fun as we get older. We work harder and longer than ever before, and we don’t have the opportunities just to go out and have some fun,” he says.

It seems to be a growing trend. Chris Noxon spent two years researching his book, Rejuvenile: Kickball, Cartoons, Cupcakes, and the Reinvention of the American Grown-Up, and found that half the people who visit Disney World are adults without kids, and more 18 to 34-year-olds watch Cartoon Network than any of the news channels. Noxon, who explored a world of skate-boarding mums and “playalong parents” who enjoy watergun tournaments, tag and dodge-ball, believes that the adult-play movement is a response to our hard-work culture: “There’s tremendous uncertainty nowadays and I think a lot of people tend to retreat back to a more childlike place.”

This evening’s session in Finchley is called cowboys and Indians. Forget bows, arrows and guns but keep the whooping noises (we do have catapults with paper pellets, but we are all rubbish at firing them). There’s lots of whooping during the games. The idea behind the theme is loosely metaphorical. When we were kids, we didn’t need anything more than a group of mates, some space and our imaginations to run wild. As soon as we got fed up with one game, someone swiftly thought of another and, as we lost ourselves in the euphoria, we forgot to go home for dinner and bathtime.

Next we’re happily playing grandmother’s footsteps. Manju, a 33-year-old teacher is “granny” and has her back to us. We’re all creeping up behind her and trying to reach her before she turns and sees us moving. “How scared are you feeling right now,” cries one playmate to Manju. “I’m wetting myself just thinking about someone getting close enough to touch me,” she says shrieking with laughter. Stuart gets to her first and she screams with that sort of excitement and panic that we all remember from years ago. Remember being chased after asking Mr Wolf for the time? And getting your head chopped off in Oranges and Lemons?

Hannah Merriman (yes, she does see the irony in her name), is the creative director of the Fun Federation and our host for the evening. She wants to reclaim the idea of grown-up games from the sex ghetto. “Just Google adult fun and you get a load of boobs,” she says. “We want to contribute to a shift in mentality. People’s natural playfulness comes out more easily when you create a nonsexual, noncompetitive environment. We do that by playing games where there are no winners or losers, and by creating a nonjudgmental setting, which allows you to be as daft as you want.”

All tonight’s games are loyal to the playground ethos – they’re physical, energetic and rapid. Best of all is a juggling game that degenerates into mayhem. We start by throwing one ball to each other and end up with teddy bears, cups, Frisbees and smelly socks flying around the circle.

But there’s always more to games – adults’ and children’s – than simple joy. Pien Maltz-Klaar, who has spent the past 15 years creating educational play for kids and grown-ups, says: “The games we played as children almost prepare us for the hard knocks in life, such as dropping down dead in ring-a-ring o’ roses and being hunted in hide and seek,” she adds. The exercise can’t be bad, either. In Germany, councils are building playgrounds for pensioners, to keep senility at bay.

We’re not quite at that stage yet, but Mela, a fortysomething psychologist, is trying to catch her breath after completing the human obstacle course that involved putting a plastic bin on her head, sliding under several chairs while being tickled, jumping through hooped arms made by a couple of people and then being squashed between the legs of two others, who are sitting on the ground making farting noises.

She says: “It’s been a great release. I needed to have some joy and balance in my life because I’m currently dealing with a difficult case.”

The organisation receives numerous requests to run corporate games days, but it turns them down, Hannah explains: “With a company the play is dictated by a need to fulfil certain objectives. We don’t do coerced fun.” We wind down by lying on our backs and weaving a giant spider’s web with cotton balls. Claire, a trainer, who has invited her friends along to celebrate her 32nd birthday, catches the mood. “I feel I’ve been at a wonderful kiddies’ party. Now I want my mum to collect me.”

Is it more enjoyable than going to the pub, club or cinema? It is a way to lose your inhibitions without alcohol, as long as you like collaborative games. I’m looking forward to coming out to play with them again soon. But right now I’m off to play kiss-chase with my husband.

thefunfed.com 020-7841 8934

Send in the clowns . . .

Nose to Nose clowning workshops. Games, warm-ups and fun help participants to be spontaneous and allows them to free up their creativity before they begin to explore clowning. Adults are encouraged to find the clown within themselves.

Available to individuals, groups and companies. members.aol.com/nosetonose 01342-823410

Serious Fun Events organise themed party nights and innovative corporate activity days. From casino and poker sessions to cybertag (playing chase with lasers, paintballing without the pain), school sports days to juggling, limbo and steel drum percussion workshops. The days are tailored to break down barriers and build relationships. seriousfunevents.co.uk 01527 559559

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