I found that individuals who release the most oxytocin -- I call them `` oxytocin-adepts '' -- were more satisfied with their lives compared to those who release less oxytocin . Paul J. Zak : I spent a decade trying understand why humans are usually moral . His new book reports how brain chemical oxytocin motivates moral behaviors . He also tests Aristotle 's theory that practicing virtue made one happy . Comment:
Paul J. Zak : I spent a decade trying understand why humans are usually moral . His new book reports how brain chemical oxytocin motivates moral behaviors . He also tests Aristotle 's theory that practicing virtue made one happy . Comment: