[HarshTruth]

Women earn lower because they choose to earn lower. Men face more pressure to earn a higher income than women, so naturally men dominate the high income fields. Then, once married, it makes more sense (economically) for the lower earning partner (the woman) to become the primary parent further widening the pay gap.

Want to fix it? Tell women to instead (statistically, as a group) start marrying down in income. Then men will face less pressure to earn a high income (and be able to, like women now, marry up for economic security), so will have more freedom to choose, and pay gaps will equalize.

The reason women go into non-profits is that it doesn't significantly effect their sexual selection. A man who does so would be significantly limiting his sexual opportunities. You don't need neuroscience to explain it. Men face every economic pressure that women do AND a sexual pressure. So naturally men earn more.

I would also be hesitant to try and fix it because the entire human endeavor is built around the male's desire for high status, which is fundamentally sexually motivated. Fix it and humanity stagnates.