[brc]

5 sons in a row? You should publish a book on how to father sons! That looks like a non-random result.

I agree with you in that the controlling factor is really just how much parental time is spent with the children. Closer spacing of children is likely to stretch parental time, but this is something a determined parent can easily overcome, even if just by being aware of it and correcting for it.

I would like to see a study which correlates future intelligence for things like time spent in childcare vs full time parenting. My personal belief is that a childcare effect would massively outweigh any child-spacing effect, particularly in boys, which in my experience seem to suffer from excessive childcare time under the age of 4 more than girls. I don't know if this is lack of male childcare workers or a biological difference in boys.

[graywh]

There already is a book. It works. http://www.amazon.com/How-Choose-Sex-Your-Baby/dp/038548562X