This document summarizes chapter 8 of the book "Understanding Intercultural Communication Second Edition" which discusses what causes biases against outgroups. It covers several topics: 1) human perception tendencies and how they can lead to biases, 2) ethnocentrism and the development of stereotypes, 3) how ingroups and outgroups are formed and the attribution biases that can result, 4) how prejudice, discrimination and racism can develop as a "shattered lens", and 5) recommendations for reducing biases through self-reflection, education and positive intergroup contact.