Claims xenophobia is documented in almost every animal group displaying higher forms of social organisation
Natural selection favoured genes that caused humans to behave altruistic towards members of their own group, but intolerant towards outsiders.
Show and Wong
Annotations:
Mechanisms that prompt suspicion of strangers favoured by natural selection, as it enabled ancestors to avoid attack, and leave more offspring.
MacDonald
Annotations:
Evolutionary perspective. It is adaptive to to exaggerate negative stereotypes of outsiders, as overperception of a threat is less costly than underperception.
Podaliri and Balestri
Annotations:
Evidence of xenophobia tendencies in Italian football crowds, like Lazio players performing 'Roman salute' to extremist fans.
Territoriality
Annotations:
Protective response to an invasion of territory.
Aggressive displays by sports teams prior to match serves to intimidate opposition.
Adaptive for ancestors as allowed them to defend resources in their territory.
Neave and Wolfson
Annotations:
Football teams playing at home are more likely to win than the visiting team, due to a surge of testosterone (an evolved drive to defend territory).
Team members who felt a burden of defending territoty was on them, then they experience higher levels of testosterone.
Foldesi
Annotations:
Found support for the link between xenophobia and violent displays in Hungarian football crowds.
Racist conduct of a core of extremist supporters led to an increase in spectators violence.
Lewis et al
Annotations:
Football fans. Crowd support rated significant factor contributing to home advantage.
Fans felt responsible for inspiring team victory, taking credit for distracting the opposing teams.
However, the precise way in which displays of support have an effect is hard to pinpoint.
Moore and Brylinsky
Annotations:
Measles epidemic caused quarantine caused 11 American basketball games for 2 teams to be played in absence of spectators. Siena Saints-9 away games analysed. 5 with spectators, 4 without.
Scored an average of 76.25 in front of spectators, and 86.20 in the absence of.
Display of support home crowds didn't increase performance.