Cats are predominately solitary hunters. If they do not hunt, they do not eat and they do not live. And because animals only do what they want (people sometimes do what they "should", but not often) cats want to hunt, in proportion to its importance to their lives. And if you've ever seen a cat sitting in a window staring at birds you know exactly how intense this desire is. But note, this is not just hunger, or a desire to be fed. All of the actions that would lead to food are individually rewarding to a cat. This obvious if you observe almost any house cat.
I have a cat. She is beautiful, loving, affectionate and fat. Her name is Baby Cat for reasons to mundane and predicable to relate. She did however have a good part of her upbringing in a barn, by a barn cat. Baby Cat will hunt the shit out of a mouse. Or a laser pointer.
But why? She clearly, Clearly doesn't need the food. Because the only way for a species to be a success is for its members to be driven to do what kept them alive in the context
in which they evolved. These drives are not "to do" lists, they do not update quickly or easily. So animals are stuck with the desires, habits and abilities that led them to success.
But as my lovely cat's desire to hunt proves, that the behavioral mechanisms that led her species to great success have totally failed to update in the presence of dry kibble (or laser pointers). And we as human beings face a very similar set of problems. Our evolved behavioral mechanisms have also not had time to adjust in the face of cars and metropolises. We are stuck wanting to do what was evolutionary successful before the agricultural revolution, never mind the industrial.
The field of study that looks at these evolved behavioral mechanisms is Evolutionary Psychology. One of the big problems with the field is that we don't know exactly what circumstances we evolved in or how we behaved in them. This means that any argument that say's "we used to do x, which is why we now want to do y" is on inferential ground at best.
That being said it is clear that we did not evolve to live in large metroplexes with literally millions of strangers within walking distance. But here we are, a naked ape living in our own constructed environment with drives that made sense somewhere in Africa 100,000 years ago.
And we clearly have a sex drive that is uncomfortably intense given our recent (read 10,000 years) history. What exactly the cause of this discomfort isn't clear. I like the story put forward by the authors of Sex at Dawn, but those are controversial. Either way we evolved in a way that leaves us with a sex drive that people have been trying to repress for 1000's of years. This is not because of original sin, but because animals evolve slowly, and environments sometimes change quickly. The resulting mismatch can look anything from silly to suicidal.
In the case of our sexual appetites the mix of cultural and technological change has seriously altered how people feel about sex and what can be done safely. Presumably our desires were adaptive while we were evolving. But after the agricultural revolution those desires needed to be modified by social constructs to keep them in line with what was safe. And since the creation of modern medicine and barrier protection, behaviors that would certainly lead to ruin can now be done with a modicum of safety.
