I don’t know – I have no personal judgment as to which idea makes sense, although the evolutionary biology-based explanation, basically the botulism one you explained above, always appealed to me because I love evolutionary just-so stories…

Stoffregen instead argues that motion sickness comes from the brain’s persistent inability to modulate the body’s movements in a challenging environment. Postural instability the inability to maintain balance was considered a symptom of motion sickness. Not so, Stoffregen says. Although postural control relies on sensory feedback, motion sickness is really a sign that the motor-control system is going haywire.

So, our inability to keep our balance when we’re dizzy may actually *make* us nauseous (rather than being a result of motion sickness). So, perhaps my tongue-in-cheek question underneath the photo — of whether dervishes get dizzy — is actually right on. They don’t get dizzy because they’ve trained themselves to maintain good balance and control their posture.

I’m also reminded of my experience in contra dancing, which involves a lot of spinning and twirling. New dancers get dizzy. Experienced dancers know to look into each others eyes (so you don’t see the walls of the room whipping past). So then the question becomes — does not seeing the walls whipping past help you avoid dizziness because (a) you keep your balance (Stoffgren’s theory) or (b) you avoid the disconnection between your eyes and your body (the original theory)? Or perhaps both.