(1) They show a lack of concern for others. A bitter person cares very little about anybody else. (2) They're very sensitive and touchy. For instance, if a bitter person walks into a room where two other people are talking, and those people get quieter as he walks in, the bitter person thinks, “They're talking about me.” (3) They become very possessive with just a few friends, and rarely ever have any really close friends. They also have an unnatural fear of losing their friends. (4) They tend to avoid meeting new people. (5) They show little or no gratitude at all. (6) They will usually speak words of empty flattery or harsh criticism. (7) They hold grudges against people, often for a long, long time. They find it extremely difficult to forgive. (8) They often have a stubborn or sulking attitude. (9) They are usually unwilling to share or help anybody. (10) They end up experiencing mood extremes - very high and happy one minute, and the next thing you know, they're so low they can reach up and touch bottom.
Winkie Pratney, 3/20/2012