Polar plunges and shark swims: why travel makes even cautious people daredevils

Courageous travel comes in many forms. Selecting a window seat on Ryanair, ordering a biryani with extra chilli in Tamil Nadu, trusting a Colombian taxi driver who "knows a shortcut" and telling your wife to "calm down" spring readily to mind. Some are more dangerous than others, but they all require intestinal fortitude, especially the biryani.

This subject of heightened holiday heroism has occurred to me from time to time. Other than my ill-advised response when my wife was directing me how and where to park in Paris, this question has generally been contemporaneous with me asking myself WTF I was thinking when I found myself skydiving in Busselton, abseiling down a waterfall in Tahiti, sampling the wares at an Amsterdam coffee shop, driving at 240kmh on the Autobahn, swimming with sharks in the Solomons and lying down to slurp running glacier water in Alaska. Among several other audacious moves that are too embarrassing or stupid or illegal to mention.

And I'm not alone. I've seen mates tackle double black diamond ski runs when they've barely mastered the snow plough, eat Sardinian sheep milk cheese with live maggots, and cheer for Arsenal at Tottenham Hotspur's home ground. Sure, blokes are natural-born idiots, but I've seen all sorts attempt similar heroics when travelling overseas.

So why are we bolder on a break? What's with the vacay cray cray? Was a dose of adrenaline infused into the warm face towel before touchdown?

It's one thing to step outside your time and comfort zones; quite another to take a polar plunge in Antarctica, line up for "The Vomitizer" rollercoaster or argue with security about the missing apostrophe at Caesars Palace in Vegas. And I posit that those crazies who take door-hanging selfies on the Kandy to Ella train in Sri Lanka are unlikely to do anything along those "lines" on the 4:15 to Parramatta.

Psychologists who delve deeper than the "blokes are idiots" hypothesis point to reasons such as the "Removal of Predictable Routines", in which a new environment extends the boundaries of what you believe you are capable, the "Brain Reward System", in which novelty and adventure release a bunch of feel-good chemicals, and the "Anonymity Effect", which reduces the fear of embarrassment or failure in front of people you know you will never see again. These all sound plausible, but looking back, I can variously attribute my own overseas bravado to the "Impressing Chicks Routine", the "Look at Me Reward System", and the "Tequila Effect".

Whatever the motivation, fearlessness in foreign climes is definitely a thing. Stick us somewhere else in the world, and we turn into Braveheart. We're lining up to bungy, munching on grasshoppers and singing Never Been to Me at cruise ship karaoke.