Many years a go I worked one season as a pilot flying air tours in the Grand Canyon. Like this http://www.airvegas.com/tour_info.php?id=24, but in a similar-but-smaller airplane about 2/3rds that size.
My personal record for a single flight with 9 passsengers is 32 bags of puke. All 9 participated; there were no abstentions.
“Hey! Garth, get it together, man. 'Cause if you hurl, and I catch a whiff of it, man… I’m gonna spew. And if I blow chunks, chances are someone else is gonna honk, alright? And that’s gonna set off a parastolic reaction, alright?”
I’ve seen it happen on a plane. Oh, not so dramatic, but even the people that are not feeling badly start to, when they smell all that puke. I was one of the last ones to start throw up.
But it isn’t like people running around and screaming. Especially in a plane where everyone has sickness bags. We all just went for our bags. Probably 2/3s of economy class was sick - I had no idea what was going on in first class.
One of the funniest scenes in any movie, EVER, is the scene in The Sandlot where they all eat the chew and get on the tiltawhirl. I laughed so hard the first 100 times I saw that. Very funny.
At the risk of fancying yet another Just-So Story, I wonder if “contagious puking” was selected for-usually people would all have eaten the same thing (mammoth meat, say), and the first person to get sick might be a warning that tonight’s meal isn’t going to be all that healthy.
I have heard that theory. And I have heard that contageous puking is more common among children, who are typically more sensitive to spoiled or poisonous food.