Prof. of Behavioral Economics, Dan Ariely,

“On an intuitive level most of us understand the deep interconnection between identity and labor… ‘What do you do?’ has become as common a component of an introduction as the anachronistic ‘How do you do?’ once was—suggesting that our jobs are an integral part of our identity, not merely a way to make money…”

Here is Prof.Ariely describing the psychology behind how we view labor: