As World Cup fever sets in, increased hooliganism and soccer (football) related violence are legitimate international concerns. Previous research has linked sports-related hooliganism to ‘social maladjustment’ e.g. previous episodes of violence or dysfunctional behavior at home, work or school etc. However, social bonding and a desire to protect and defend other fans may be one of the main motivations not only for football hooliganism, but extremist group behavior in general, according to new research.
Source: https://www.sciencedaily.com/releases/2018/06/180624001202.htm