Because associating with successful others increases their positive feelings about themselves. It also changes their hormone levels. If their team wins their testosterone level shoots up and they feel good. If their team loses, their testosterone level goes down and they feel miserable. Their team's success also affects their cortisol levels.
“Because associating with successful others increases their positive feelings about themselves. It also changes their hormone levels. If their team wins their testosterone level shoots up and they feel good. If their team loses, their testosterone level goes down and they feel miserable. Their team’s success also affects their cortisol levels.”
In other words they are displaying the symptoms of an addict.