Positive Affectivity (PA; Extraversion)

Susceptibility to positive affect. Individuals high on trait extraversion, relative to those low on trait extraversion, are more likely to have an appetitive motivation system that appears to motivate approach behaviour through positive affect. As such, individuals who are high on trait extraversion are likely to be sensitive towards positive affect given their heightened reactivity towards rewards.

Reference:
Larsen, R. J., & Ketelaar, T. (1989). Extraversion, neuroticism and susceptibility to positive and negative mood induction procedures. Personality and Individual Differences, 10(12), 1221-1228. Doi: 10.1016/0191-8869(89)90233-X

Weiner, B., Graham, S., & Chandler, C. (1982). Pity, Anger, and Guilt: An Attributional Analysis. Personality and Social Psychology Bulletin, 8(2), 226-232. doi: 10.1177/0146167282082007.

Goetz, J. L., Keltner, D., & Simon-Thomas, E. (2010). Compassion: an evolutionary analysis and empirical review. Psychological Bulletin, 136(3), 351-374. doi: 0.1037/a0018807.