Psychological Tendencies

“All human beings seem to have three psychological tendencies. The first is to have our emotional state influenced by the emotional state of those around us. The second is that our feelings about our own situation are influenced by how we see your own situation in comparison to that of others. And the third to that we like pleasure and try to avoid discomfort or pain.”
I believe that Hume might have done this by using examples of daily living. He would ask people to question how they feel when confronted by different situations. He would give examples of how behavior is situational and can change no matter what the personality of the person is. Then, he would support his second psychological tendency by pointing to the fact that people rely on other people’s approval in order to feel accomplished. People are no longer satisfied with intrinsic fulfillment, they seek external success. Then, he would point to the extremes that people go through in order to ignore pain. People will avoid situations and will ignore paths that cause excess exertion of energy and time. People would rather take the easy route, even if it is less beneficial.
I am interested to read how Hume actually does this in A Treatise of Human Nature.