[Harry K.]

Yep. Everything needs a reason, statistic or whatever. It's all about cognitive behaviour. Making sure you don't overload the mind with too many options.. Simplicity without expense etc.. It's asif you need to believe that everyone freaks out when given an out of the ordinary placement and you need to make it so obvious it's impossible to mistake. (I'm speaking from a Website perspective as that's what I know) Most big sites nowadays are designed on a "Social engineering" aspect of UI/UX, they have teams of experts that know how the mind works and reacts to certain placements, colors, wording, styles etc.. You can guarantee the smallest change you see on Facebook, or Twitter etc.. there will be loads of articles on why and what it improves/helps.