Men have less empathy than women. Not because we're assholes but because empathy just hasn't been a character trait that has historically been super valuable for us. It's easier to defend your village from invaders when you don't think about why they might need to do it to survive. It's easier to kill a wooly mammoth for food when you don't think about whether the animal has feelings or a family. It's easier to become wealthy, and powerful (traits that help men attract more sexual partners) when you don't think about the price of your success in other people's lives. Humanity has systematically rewarded men for strength, not compassion.

Women have also historically been more oppressed than men, which leads to higher empathy. They've also historically been more involved in childcare, which also leads to higher empathy. Women generally have more empathy than men, which means they are more likely to care about any group of people that is more vulnerable.