This has always been a puzzle to me. I, like many people I know, have a tendency to sneeze when going from the dark into bright sunlight. I think it's a pretty widespread response, which implies there is a genetic advantage.

I've pondered this, and wonder if it's because a sneeze peps up your olfactory senses, so that our ancestors, when going from the forest onto the plains, would be better able to smell trouble.

On the other hand, a sneeze would alert predators of your presence, which would in my view tend to be a sorta bad thing. Unless, of course, the sneeze tends to startle the predators so they jump and run.

This response is not limited to humans, by the way. Many dogs do it. The dachsunds my parents owned were particularly susceptible.




TEd