| August 27, 2012

Why do we love who we love? Scientists are still puzzling over this one (perhaps for personal as well as professional reasons), but new tools for looking inside our heads are telling us more about the brain in love and sex.

Love, it turns out is not blind. Or rather, sexual desire isn’t: men and woman are both turned on by visuals as evidenced by the popularity of pornography. Scent is even more powerful.

And that flame of desire is near instantaneous. An MRI study of where love works in the brain found that humans know, in the blink of an eye, if someone is attractive; your brain can tell in a fifth of a second or less whether you desire someone or not.

But that’s just sex. What about passionate, deep, everlasting love? That, too, can be seen in the brains of the happily mated as it activates specific areas connected with long-lasting attachment as well as pleasure.

Alas, we know less about how we choose our long-term mates, but psychologists have some theories. One is that we all create “love maps” — ­ idealized and very individual images of our perfect other — and that we look for the person (or persons) to fit them. It’s a blueprint of your perfect mate, against which you measure and rate all prospective others. It includes your likes and dislikes and preferences in hair and eye color, voice, smell, body build, personality type, and possibly profession and income.

There are many wide-ranging theories about where such specifics come from, including a search for attachments with partners who suffered similar childhood traumas; with partners who have qualities we lack or who satisfy a need; with those who have the same level of independence as we do; with someone we think absolutely, totally and completely loves us; or with someone who mirrors our relationship with our moms or our dads. Our love maps might even lead us to someone similar to a parent with whom we have an unresolved childhood issue, as there's no doubt our first great loves were our parents, and the way we learned our attachment style seems to carry over into our adult lives and romances.

But what about the old rule that opposites attract — the staple of many a romantic novel, film or play? Well, that may be, but usually not for long. Research actually shows we’re twice as likely to be attracted to someone with whom we agree on six out of ten issues, which all could help explain why arranged marriages seem to have a greater longevity rate than so-called love matches. So if you’re looking for love, maybe you shouldn’t rule out some of those blind dates your friends and family suggest.