“We put over 100 people who were madly in love into a brain scanner using fMRI. We noticed those who had fallen in love in the first eight months had a lot of activity in brain regions linked with intense feelings of romantic love. Those who had been madly in love for a longer period of time—from eight to 17 months—showed additional activity in a brain region linked with feelings of deep attachment. That vividly showed us the brain can easily fall happily and madly in love rapidly, but feelings of deep attachment take time.” – Nautilus