Many contemporary scholars, and not only popular writers, have … argued that the standard socio-economic science model requires, justifies and promotes selfish behavior. On the contrary, … opportunism in all relational contracting and exchange across time (is a) cost, not a benefit, in achieving long-term value from trade; an ideology of honesty means that people play the game of “trade”,’ rather than “steal” … .

Vernon Smith (2003). Constructivist and Ecological Rationality in Economics (Nobel Prize lecture). The American Economic Review, (93 (3), p 466