In divorce why does child custody usually go to the mother?

[LizB]

Because the mother usually cares more about getting primary custody and is more likely to ask it. A study on this very subject reflected that not only did fathers ask for primary custody less, but they wanted it FAR less. So a big part of the supposed "bias" toward mothers isn't actually bias, but rather a lack of fathers desiring or pursuing primary or full custody.

It's kind of the opposite problem of how even in this day and age, women still earn less than men even when all qualifications are equal. Yes, part of it is old-fashioned sexism (and it happens to impact women with children more than women without), but part of it is that we don't live in a culture that encourages women to ASK for higher pay as much as men. If you don't ask, you don't get, and problems like that don't magically get solved on their own.