Is there a tendency for one race to produce more twins (or other forms of multiple births) than others?
Also, do other primates such as chimpanzees, gorillas, etc., ever produce multiple births?
Chimpanzees certainly have twins on occasion. I don’t see why other primates wouldn’t.
There are differences between human populations.
anecdote warning
When I taught at a Jewish High School, it seemed to me that there were a greater proportion of twins in the school than in the general population.
Also, more left-handed children…