“Before puberty, boys’ and girls’ bodies are not all that different,” he says. “And after, they are. One of the differences is mass distribution. In women, the weight tends to be carried in the hips, and in men, in the chest. You have a big mechanical difference there.”
Again, the actual mechanics here are complicated, but generally, women tend to sway slower, but farther, and men tend to sway faster, but in a smaller area. (“Farther” of course, in the context of already-tiny movements.)
So, “at the end of the day, I think I can answer the question ‘Why is there a sex difference?’” Stoffregen says.
Women are also differently susceptible based on where they’re at in their menstrual cycles. This seems a little bonkers, but Stoffregen points out that “introducing certain chemicals [like caffeine] into your bloodstream can affect movement, why not hormones?”
So maybe puberty’s bodily changes can account for why a kid who barfs on merry-go-rounds can grow up to be an adult who cowers not in the face of metal horses. Hain also notes that “as people pass their mid-50s, they start to get less sensitive to motion, probably because of less inner ear function.”
It’s comforting to know that motion sickness is not always forever, in the long-term, but also in the short-term. It is rare that someone will go on a cruise and spend the whole time heaving over the side-rail. Both Hain and Stoffregen emphasize that people get habituated to motion over time, and feel better. Sailors, for example, can adjust too well to the rocking of a ship, resulting in mal de debarquement, or “land-sickness,” when they’re back on solid ground.
Sam Puma, a physician, former Air Force pilot, and former NASA flight surgeon, has developed a program to treat motion sickness based on habituation exercises. “In as little as one week,” the website promises, “you can begin to enjoy activities that used to make you feel ill.” Despite the infomercial-esque appearance of Puma’s website, Hain says Puma’s not just selling snake oil.
“I’ve sometimes used these exercises to treat patients,” Hain says, “though they always get so sick they never want to finish it. I’ve never been able to get anyone through the whole two month [program].”
If vomiting a lot now to avoid vomiting a little later is not so much your style, there are other options, though none are perfect. Over-the-counter antihistamine pills like Dramamine are often used to treat motion sickness, though only those with a sedative effect seem to help, according to pharmaceutical company Merck.
“Any sedative will tend to make you move less or wish to sit down as opposed to stand, lie down as opposed to sit,” Stoffregen says, though Dramamine does not work for him, personally. “Anything that will stabilize the body will help.”
Scopolamine patches are also sometimes prescribed for motion sickness, and may help by reducing nerve activity in the inner ear.