Vanderbilt anthropologist Ted Fischer describes the evolutionary reasons for falling in love and how modernity has urged it along.

Question: What is romantic love?

Ted Fischer: We define romantic love as an intense for another with the expectation that it’s going to persist into the future.  And that distinguishes it from lust, which is generally fleeting, and also from more companionship love, which doesn’t the intensity of desire that you want to possess the other in some way. Often it’s characterized by some sort of irrationality.  Not doing what a rational person would do in those circumstances.  Buying a large gift when you really don’t have the money, or going out to a really nice restaurant, or making that that extra sign of one’s love that you hope will attract the other.  And so, really it’s a bit of craziness, romantic love.  We’re a little bit off kilter when we’re in love.  And that’s the way we talk about it.  It’s like we’re under water in some way, or we’re overwhelmed by love.  Crazy in love.

Question:  What’s the evolutionary advantage of romantic love?

Ted Fischer:  Well there’s some clear evolutionary advantage to falling in love, and especially for pair-bonding, a male/female bond, and let’s think back, you know, 20 - 30,0000 years ago when our ancestors were living on the Savannahs in Africa.  Human infants are incredibly helpless, and it’s very hard for one person to take care of an infant and also gather food, and hunt food, and run from predators.  And so, having some sort of core or familial group makes lots of sense.  And so, there are evolutionary psychologists and biologists who would say, “we evolved a propensity for romantic love to create families.  So that it’s not just the mother taking care of the child, but a father as well.”  Mothers have this natural need to take care of children.  The child comes from the mother, has to breastfeed with the mother.  Fathers are less inherently attached to the child.  And so, there is a theory that males evolved this propensity to fall in love so that they would stick with their partners.

Question: Are there drawbacks to romantic love?

Ted Fischer:  An evolutionary biologist would say, “Yeah, we have this propensity that’s evolved that creates all of these positive side effects for us socially,” creating for example.  But sometimes those propensities can go out of control.  We seem to have a propensity to eat fatty foods, for example, and yet in the society in which we live that’s not so adaptive as it was 10,000 years ago, we should have eaten fat every chance we got.  And now we have to sort of fight against ourselves and resist all of that fat. And so it doesn’t necessarily -- it’s not necessarily a contradiction that we could have evolved -- I keep saying propensity, we could have evolved a propensity for romantic love, and yet it’s counter-adaptive some times, too. But you do find suicides, for example, and that’s as about as dramatic as it gets.  A number of cases in India, for example, of young men and young women in arranged marriages or going into arranged marriages and committing suicide rather than spend their life without their truly beloved.