Derek mutters to himself, "What's in it for me?" before agreeing to help another person shows that he has overcome the problem of self-interest in motivation.

Self-Interest

Acting in a way that is beneficial to oneself, often without regard for others.

Motivation

Concept with two widely used meanings: (1) an internal state that leads to effort expended toward objectives and (2) an activity performed by one person to get another to accomplish work.