happiness sensor

I wish there were a sensor that would capture happiness. If you had a child exposed to several moods: as in buttons, colors, paintings, machines, letters, computers, biology pictures, introduction of novels… what would make that person’s heart jump.. ? In my case, it would be a drawer of craft material… pastel buttons and lace and colors.. Same for the type of people we like to be with.. those who bring out a nice conversation? Those who sit in a way that suggests that time is eternally immaterial… if we relaxed forever on a swing..