it was leah pearlman and justin rosenstein and a few other developers that have this idea like facebook back before the likes of him if he wanted to say something was good, you had to write a comment. but you basically understood a lot of people are too busy and they are not going to write that comment so they wanted to in their own words unlock positivity by a button that would be very simple. it was originally going to be called because some button -- awesome but in. so they create this thing and sure enough it does exactly what they say it is going to do. suddenly people like this is great. there's a nice feeling coming in. over the next year or two they began to notice these weird problematic side effects. one of them is they created a new quantification, there is a new number to stare at and it's a big number like how many people liked your post. they understood it would be nice to get the approval but failed to predict people would become obsessed with pushing it over and over to see if the number got higher and would get weirded out if it didn't go up for other peoples were bigge