Why does Ingrid initially dislike Vivian in the novel, Disorientation?

At the start of the novel, Ingrid regards Vivian as her arch-nemesis. However, following her discovery about Chou, Ingrid tries to befriend Vivian. She admires Vivian's intellect and courage. She also envies her ability to invest in social justice. Though the two never become close friends, Ingrid does learn from Vivian.