We remember happy people because we are sensitive to positive social signals
According to Duke University researchers, we're not only attracted to people who smile but we also tend to remember their names. In a 2008 fMRI (functional magnetic resonance imaging) study, Professors Takashi Tsuldura and Roberto Cabeza showed subjects pictures of smiling and unsmiling individuals, followed by their names, e.g. "Nancy," "Amber," "Kitty," and so on. The results found that the subjects' orbitofrontal cortices—the region of the brain associated with reward processing—were more active when the subjects were learning and recalling the names of smiling individuals. "We are sensitive to positive social signals," Cabeza explained. "We want to remember people who were kind to us, in case we interact with them in the future."
We do not love people so much for the good they have done us, as for the good we do them.
Love does not consist of gazing at each other, but in looking outward together in the same direction.
It is not a lack of love, but a lack of friendship that makes unhappy marriages.