Should we believe textbooks when they make claims like ” where people have a strong national identity, they may be more likely to have negative attitudes toward groups they perceive as different to themselves.” I look at:
Falomir-Pichastor, & Frederic (2013). The dark side of heterogeneous ingroup identities: National identification, perceived threat, and prejudice against immigrants. Journal of Experimental Social Psychology, 49(1), 72–79.
to find out.