Studies have also linked the concept of ethnic identity with ethnocentrism and prejudice. While ethnocentrism is defined as a feeling of hostility towards out-groups, prejudice is a feeling of hostility toward a specific out-group (Adorno, Frenkel-Brunswik, Levinson, & Sanford, 1950). The term ethnocentrism was first popularised by Sumner (1906), which argued that there is a positive correlation between in-group belonging and out-group hostility.
Previous anthropological, psychological and behavioural research has investigated inter-group conflicts and inter-group prejudices and tracked their origins up to ancestral times (Schaller & Neuberg, 2008). In fact, emotions, behaviours as well as cognitive reactions can lead to creating prejudices against out-groups, which makes the latter a threat (Neuberg & Cottrell, 2006). With regard to understanding human behaviour, studying primates, the closest species to humans, can shed a light on numerous factors.
In terms of sex differences, studies found that males demonstrate more hostile behaviours towards out-groups than females (Carpenter, 1974; Cheney, 1986; Wilson & Wrangham, 2003). This is especially observed among primates, notably male chimpanzees, who patrol in their territorial boundaries. They tend to particularly show hostile behaviour when they encounter other patrolling male chimpanzees from out-groups (Goodall, 1986; Wilson & Wrangham, 2003). Hostile behaviour among male chimpanzees is higher than female chimpanzees, most likely because patrolling and raiding were primarily exclusive to males (Chagnon, 1988). However, in terms of reproduction, female chimpanzees can seek out mating opportunities in other groups if possibilities are limited within their own group. This increases tolerance and acceptance potential among female chimpanzees towards other groups (Goodall, 1986; Wilson & Wrangham, 2003).
Prejudices and stereotypes vis-à-vis other groups are flexible variables coming from evolutionary roots. Human beings are likely to see out-groups as a threat. However, this tendency depends on to which extend the individuals see themselves exposed to a potential threat. The more an individual feels that he is vulnerable to a potential threat, the more he is likely to fear the out-group, and therefore, hold prejudices and potentially demonstrates aggressive behaviour towards it. However, if an individual does not feel vulnerable vis-à-vis a given out-group, he would not hold prejudices against it and would be more tolerant (Schaller, Park, & Faulkner, 2003; Schaller, Park, & Kenrick, 2007).
The same principle also implies such effect in sex differences. Men are more likely to feel vulnerable and sensitive towards out-group threats because of prejudices and stereotypes, and may express a cautious, or even an aggressive behaviour if they feel like being in an advantageous situation. Therefore, men can be more sensitive to out-group cues and hold prejudices against them than females (Schaller & Neuberg, 2008).
One can also investigate in which situations lower levels of ethnocentrism can be observed. Previous studies repeatedly found an association between high levels of education and lower levels of ethnocentrism (Bobo & Licari, 1989; Case, Greely & Fuchs, 1989; Hello, Scheepers & Sleegers, 2006; Nie, Junn & Stehlik-Barry, 1996), and other studies found that education is an important independent variable of ethnocentrism (Hello, Scheepers & Sleegers, 2006; Nie, Junn & Stehlik-Barry, 1996). It is argued that education is a major factor that influences the individual’s value pattern, and therefore, lowers the levels of ethnocentrism. More specifically, it is during adolescence and early adulthood that individuals interact with others in educational institutions and learn how to release their ethnocentrism and be more tolerant towards dissimilar groups (Hello, 2003).
One of the major theories suggesting a high correlation between high levels of education and low levels of ethnocentrism is the socialisation theory (Bobo & Licari, 1989) and the intergroup contact theory (Coenders & Scheepers, 2003). The socialisation theory argues that education is linked to the individual’s cognitive sophistication, which is also related to a negative association with ethnocentrism, while the intergroup contact theory asserts that highly educated individuals tend to have a larger network of personal contacts, thus leading to lower levels of ethnocentrism.