"Nothing about the concept of positive interdependence requires that members of the group avoid conflict, and there are good data to suggest that they should not do so."

“Punishment and reward proceed from basically the same psychological model, one that conceives of motivation as nothing more than the manipulation of behavior.”

“Someone who thinks well of himself is said to have a healthy self-concept and is envied. Someone who thinks well of his country is called a patriot and is applauded. But someone who thinks well of his species is regarded as hopelessly naïve and is dismissed.”

“Children learn how to make good decisions by making decisions, not by following directions”

“Very few things are as dangerous as a bunch of incentive-driven individuals trying to play it safe.”

“It doesn't matter how motivated students are; what matters is how students are motivated”

“Most things that we and the people around us do constantly... have come to seem so natural and inevitable that merely to pose the question, 'Why are we doing this?' can strike us as perplexing – and also, perhaps, a little unsettling. On general principle, it is a good idea to challenge ourselves in this way about anything we have come to take for granted; the more habitual, the more valuable this line of inquiry.”