I'm not sure. In the past I've called it "personality love". Loving someone primarily for who they are on the inside. Probably a throwback to my old Christian days when I was told by others and believed myself in the concept of a "one true love".
As for my own personal views of love, as an atheist who is heavily into evolutionary psychology I have more of an animalistic view. Primarily a look based one, but gradually I'm coming to understand that the physical features we desire have psychological underpinnings.
Even as a young Christian... I always found it strange how attractive people's one true love tended to be other attractive people, and ugly people's true love was other ugly people.
Still... it seems like I'm missing something compared to what I witness from other people. Women just seem interchangeable to me. One pretty woman isn't much different than another pretty woman.
I do have some sense of attachment. I do feel something different for people I've known longer compared to those I don't... but still, it feels weak. Certainly not something that can inspire wanting to marry someone.
My parents we extremely loving. Sometimes I wonder if I was simply desensitized because of that. Like it was something I never went without. Maybe in some sick way, part of a healthy upbringing is having parents who are not always loving. Not sure how to explain it.. I was quite secure with the idea that my parents loved me, yet I still felt distant from them and could never really feel it. Whenever I was hugged, I wanted to feel something... but it was just empty.
I do wonder if maybe I'd have a stronger sense of love if I didn't have that security.
For the most part I think it's just genetic... more specifically I have some mutation that makes me experience emotional empathy differently. I do know on my father's side.. most of his sisters never married... and both my sisters seem to never date. One even said she doesn't quite know what love is. Probably a genetic component behind it.