There is, however, a self-control side effect of this automatic mind reading: It activates those very same goals in us. Psychologists call this goal contagion. Research shows that it is surprisingly easy to catch a person’s goals in a way that changes your own behavior.
For example, in one study, students caught the goal to make money just from reading a story about another student who worked over spring break. These students then worked harder and faster to earn money in a laboratory task. Young men who read a story about a man trying to pick up a woman in a bar caught the goal of casual sex, becoming more likely to help an attractive young woman who interrupted the experiment.
(The researchers confirmed that the young men believed that helping a woman increases the chances that she will sleep with them — a plausible hypothesis, although I’m pretty sure the effect size is smaller than most young men hope.)
Other studies show that thinking about a friend who smokes marijuana increases college students’ desire to get high, while thinking about a friend who does not smoke decreases their interest.
— The Willpower Instinct (Kelly McGonigal), Loc. 2911–8