UCL study establishes common biological ground for maternal and romantic love in humans. Here is a link to the abstract. This makes sense, after all, the term baby is used in both romantic and maternal contexts. Years ago a friend of mine asked me to explain "love," and my lack of elaboration or response was proof that only the miracle of God could clarify this issue. Wish I had those brain scans handy at the time.

What I would be really curious about is what the results would have been if they expanded their pool of subjects to psychologically "atypical" individuals.