Cameron Walker unpacks the science of motion sickness:
Women tend to be more affected by motion than men, particularly during their menstrual cycles. Migraine sufferers are at-risk for motion sickness, too—and women who haven’t been struck by motion sickness in the past can become more likely to get it around the two peak migraine onset periods (around age 35 and again at menopause). There may also be a genetic component to motion sickness.
Much of the motion-sickness literature reports that babies and toddlers under two are seldom victims. One thought as to why we get motion sickness is that it’s designed to stop movement that makes us unstable or involves conflict between different senses, and that avoiding this kind of movement would confer evolutionary fitness. In Brain Research Bulletin, Brad Bowins goes on to propose that motion sickness’s negative reinforcement would only work once a person could act to relieve its effects, eliminating its "advantage" in those too young to physically respond.