That people underestimate the effect a persuasive message will have on them personally while overestimating the effect it will have on others.

The third-person effect/factor.

Explanation:

The third-person effect is a prediction that occurs when a person thinks that the social media has a greater effect in influencing other people rather than himself. As the exercise details, this effect suggests that people underestimate the effect a persuasive message will have on them personally, while overestimating the effect it will have on others.

answer; conditional stimulus will trigger a conditioned response;

answer; grew into towns and cities;