science and love. interesting article, compiling several studies.
In the end, lasting love depends at least as much on behavior as biology. But the first moves are made before you’re even born.
Interestingly, brain scans in people who’d recently fallen in love reveal more activity related to love than sex. “Romantic love is one of the most powerful of all human experiences,” says Helen Fisher, an anthropologist at Rutgers University. “It is definitely more powerful than the sex drive.”
and another article here