Not just happiness. I hate when people say happiness, when they mean many other things. Happiness isn't everything; this experiment is still true for those who realize that seeking only happiness is shallow. Help others, and you gain much deeper things.
What about Fear of water? Phobias: xenophobia definition is a bit simplistic; yes 'strangers' but also more towards the fear of foreigners. Usually, used socially and culturally than just 'strangers' but I digress.