Playing With Mismatches

I like this woman I've been seeing, but she's really in love with me. I've been clear that I'm not ready to get more serious and that I'm really never going to be up for that with her. She's chosen to stick around, but her best friend called me crying, saying I'm breaking her heart. (Yikes!) Is it wrong to stay with somebody whose feelings are much stronger than yours?

--Troubled

She sees the two of you getting old together. You see the two of you getting together for sex on Friday. The French make this sort of mismatch sound sexy and fabulous, calling what she's feeling "le douleur exquise" -- the "exquisite pain" of wanting somebody you can't have. But look under the hood and you'll see an ugly stew of hormones and the psychological gotchas called cognitive biases -- unconscious errors in reasoning -- leading to an acute case of adult-onset puppy love. Some would argue that this woman is worshipping at your altar of her own free will (laying if not crops and a goat at your feet, then undying love, Doritos, and beer). The truth is, a cognitive bias called the "sunk cost fallacy" probably has a good bit to do with her sticking around. This describes our tendency to be irrational "investors" -- deciding whether we'll continue putting time, energy, and/or money into something based on what we've already put in. This is dumb, because our initial investment is gone, and throwing in more whatever won't change that. The rational approach would be basing our decision on what kind of payoff we're likely to see down the road. Unfortunately, though we humans have a reasoning department built into our brain, cognitive biases can keep it a plastic-wrapped no-go zone, much like my late grandma's living room couch. Love is not always 50/50, but it also shouldn't be, oh, 90/10. Eventually, if you have a conscience, taking advantage of her futile hopes will prey on you (if it hasn't already). And sooner or later, she's likely to resent and maybe even hate you for sticking around to never give her what she wants -- instead providing the dating version of "Hey, we don't sell what you need at this store, but please hang out here till we go out of business."