Let’s say I have a son named Bo (which I do). But if you don’t have children of your own let’s say Bo is a nephew, an endearing child from the neighborhood, or just a kid you happened to meet that you care about. 

Now that we’ve met Bo, we can make another assumption fairly safely: Bo will have children of his own or meet another kid someday, similar to how we met Bo. Let’s call that child Lily.

I care about Bo. I love Bo. Bo’s future happiness, health, peace, freedom, and prosperity matter to me. But we also know Bo’s future happiness and peace is tied up with Lily’s. If Lily’s future isn’t bright, Bo will be unhappy. If Bo is unhappy, because we love Bo, we are unhappy. 

But Lily will also have a kid she cares about someday too, presumably. Let’s call him Miles. In the same way as before, if Miles’ future isn’t bright, we are unhappy. And so on.  

Because of this love I have for Bo (and the love I have for Lily, Miles, and others, transitively), I’m more willing to make sacrifices for them now. Intergenerational love makes my thinking more long-term than it would be otherwise.

In other words, kids are important, because they extend the time horizon by which we make decisions, perhaps by several generations. 

But love is the key here. If there isn’t love across generations, none of this transitivity and recursive thinking ever happens. If I don’t love Bo, in this example, I will never love Lily, Miles, or anyone after. My thinking won’t be as long-term.

Cohesive, loving, families aren’t just nice to have, in a way, perhaps the future of our species depends a little bit on the love they create and how that love makes us sacrifice now for the benefit of future generations.