Why are humans so sexually passionate?

Because our child was born too early.

Yes, you're not mistaken. Humans have developed such a strong sexual desire precisely because our children are born too early.

The reason why our baby was born prematurely was that our brain was too large, so the baby had to be born before their heads became too big to pass through the birth canal. This means they were born completely useless.

The young of other mammals are usually able to stand, walk, and suckle from their mother's nipples to feed themselves. However, human newborns cannot even lift their heads. They do not become fully dependent on adult siblings until at least the age of seven (in modern society, it is more often 17, and sometimes even 27 or older!)

Other mammalian mothers can take care of a litter or even multiple litters of young ones alone, because the young can adapt well to the environment or follow their mothers when the mothers go hunting. But the young of humans cannot do this. Human mothers cannot take care of their young alone (at least in prehistoric times, before there was single-parent mother pension). As humans evolved, both parents, or even the entire tribe, needed to jointly raise the young to reach the age when they could survive and function. Humans evolved sexual behavior to maintain their connection while raising the slow-to-mature children.

This fact also dispels the myth that "men are naturally inclined to spread their genes widely". This is not a reproductive strategy of humans. If men were to "scatter seeds" everywhere and leave mothers to raise the children alone, human beings would never have evolved to the current level.

The sexual behavior of other mammals (with the exception of most primates) is solely for reproduction. They engage in sexual activity only when the females are fertile, and this act itself does not bring any pleasure. It has no other purpose beyond reproduction.

However, humans can engage in sexual activity at any time, and it is extremely pleasurable (or it should be!) 。 Even long after the reproductive years have passed, we can still enjoy a wonderful sex life. This might be because when the physically stronger parents are occupied with other tasks (such as skinning animals, harvesting crops, etc.), they need the happy grandparents to take care of the children.

Sexuality has a social function for humans, a function that helps establish connections.

Sex is not just about having children; sex enables couples to feel good for each other while raising children. Perhaps in prehistoric times, people did not understand the existence of fathers, so everyone felt responsible for helping women raise children - and they were likely to have had sex together (read "Sex at Dawn" for a fascinating discussion on this possibility).

Therefore, our large brains have driven us to evolve a good sex life.

Fortunately, our large brains have a dual function - they not only enable us to have a good sex life, but also allow us to have a good sex life. Our huge brain capacity enables us to think, plan, fantasize and create - all of which are essential for a wonderful sex life!