IQ seems to be a combination of genetics and environment, as well as the test itself (the measurement tool).

And a child's mother is *both* genetics and environment.

I have no idea what the current thinking is on the complexity of human inherited traits, but the gist of what I've read over the years is that intelligence is really much more complex than "maternal genetic component".

It's intelligence even considered to be something that is directly heritable these days? I thought that too many genes and possible gene combinations were involved.