Complex behavior can be and often is genetic. A great example of this is the vastly different behavior of the zebra and lion when in close company with zebras. The zebra will engage in herd behavior, whereas the lion will try to eat one of the zebras. No amount of socialization can alter these behavioral patterns.

I can tell you that my wife and I both knew long before we were anywhere near adults that we wanted families. You know how some people know that they want to be a fire fighter or a police officer when they grow up? I knew I wanted to have a bunch of kids. The story is more or less the same for her. And my wife and I both grew up on the left, where the attitude toward having children varies from something you do after you have your career sorted to outright anti-natalism.

> . A great example of this is the vastly different behavior of the zebra and lion

We're not zebra and lions

> knew long before we were anywhere near adults that we wanted families

peer pressure is strong in our society

family is a motivation to stay alive for many

> I knew I wanted to have a bunch of kids.

Yeah I though I knew as well, much like I thought I was going to be an astronaut

Now I'm a grown up man, in charge of his life, and I know I don't care about a family

And it's not the gene's telling me, I still think about having a legacy, a mini me persisting my DNA but I know that it's just a legacy from the past where a man without a family to support wasn't a real man.

That's it, education and culture

If reproducing was such a strong genetic trait, men on heart would have been billions centuries ago

The truth is kids are family support, the more societies get rich, the less people make children

It's scientifically proven, poor need kids not for reproduction but for elderly support

Poor also make a lot of children because in poor societies kids die more easily

For all of human evolution except the last 50 years, so 6,997 out of the last 7,000 generations, the drive to have sex was synonymous with the drive to have children. Then we invented birth control. Now evolution will select for people who have a desire to have children, separate from their desire to have sex.

The idea that complex behavior can be caused by genes in animals, but somehow not in humans is incorrect. People point to culture as if it is some magical force that makes people do things, but the human ability to create and interact with culture is itself the result of genes. After all, zebras and lions don’t have culture.

And you missed my point: I grew up in a culture that did not value having children. Having children was considered an after thought, something to be done after you had attended to your career. Growing up, I only knew one family with 4 children. They were considered the weird religious family. Yet I have known since I was 12 or 13 that I wanted to have a large family, even though I grew up in a culture that would look down their noses at a family of 4 or more children.

And the argument that poor people have lots of children for financial reasons doesn’t hold up any more. It did when most people were farmers, but the poor in the developed world are no longer farmers and I don’t think there’s any way to argue that children are a net financial benefit to them.

> the drive to have sex was synonymous with the drive to have children.

that's not true!

It's not even the main drive for many apes and monkeys…

> The idea that complex behavior can be caused by genes in animals, but somehow not in humans is incorrect

But I didn't say that

I said we are not those animals and don't live by the same rules

The complex behaviour of catching a mouse in a cat is genetic

Should humans behave the same when they see a mouse?

> I grew up in a culture that did not value having children.

Oh that's even more powerful

Youth rebellion

Do exactly the opposite that your parents and people around you are doing

> And the argument that poor people have lots of children for financial reasons doesn’t hold up any more

It does now more than ever

Now that globalization is taking a lot of poor countries out of poverty

Just watch Hans Rosling's talks

If the drive to have sex and the tremendous pleasure that results from it are not for making offspring, then how did they evolve?

> then how did they evolve?

Easy: being on top of the food chain allowed us to evolve our relations beyond having an offspring

Those having more satisfactory relations formed groups that we now call families up to the point where sex today is mostly recreational

basically pleasurable sex gave us mate choice just like a bird chose the best dancer or a lioness the stronger male

pleasure instead of strength in the long run made happiness a goal in our modern societies instead of simply domination

we don't have sex just in some period of the year

we enjoy sex just like we enjoy eating or having fun

For a cat or a dog sex is not pleasurable, it's just a relief from heat, but we call it rape.

Citation needed - obviously culture and education have an enormous impact on how humans live, but given that other animals are driven to reproduce, it shouldn't be a surprise that we are also.

When child survival increases, kids per family decrease at an enormous rate down to one kid per family

https://www.ted.com/talks/hans_rosling_on_global_population_...