Why are most kids born during July/August/September ?

[Ban my account ffs!]

I think research has been done and has found that hormones that might lead to sex are highest during autumn/early winter.  It is that way for many mammal species... and regardless of African seasonal variation, it has a small effect.

Another interesting thing:  While births rise and peak in summer, unplanned pregnancies, births to unwed mothers, and births to teens peak in winter/early spring.

The reasoning is that sex among young, unwed people is most likely to take place during spring or summer after having been shut in with the parents for much of the winter.

They studied this after they found that children born during winter were more likely to commit crimes, be depressed, or come from an untraditional or broken home.  In contrast, those with summer birthdays were more well behaved and tended to belong to more traditional families.

Of course, as with any statistic, while significant... only applies to a slight correlation.  Most kids born in December are just as well adjusted as those born in June.

[Ban my account ffs!]

Christmas and New Year are nine months before, too.

Does the trend hold in the Southern Hemisphere, where it's Summer in December/January?

Even in Australia, July-September are the months with the most births, says the ABS.

It'd be interesting to see if that holds true among the aboriginal population... as compared to the white population that came mostly from the NH quite recently.