These models represent collections of individual people described by computer algorithms that capture a specific set of traits, such as a tendency to cooperate or not.

Most of the psychological theories are verbal, but words can be imprecise. If "cooperation is intuitive", it needs to state when. And what does "intuitive" mean?

Psychologists do not understand human moral behavior, because it seldom makes any logical sense.

There seems to be evolutionary logic to the human ability to cooperate but adjust if necessary. To trust, but verify. 

Our intuitions are not fixed at birth. We develop social rules of thumb for interpersonal behavior based on the interactions we have. 

Through a series of experiments, it was discovered that despite the temptation to be selfish, most people show selflessness.