What are the contributing factors that increase the likelihood of genocide?

Based on answer options I've seen for this question elsewhere, I'd list  contributing factors increasing the likelihood of genocide as these:

An example would be the genocide that occurred in Rwanda. The genocide in Rwanda had arisen out of problems created by colonialism in that country.  The Dutch colonial government had favored the Tutsi people over the Hutus. (The factor of leaders increasing tension between groups.)  That created unequal distribution of power and resources.  When the Dutch pulled out of the country, the postcolonial situation was one of great economic, political and social instability.  All of this played into the violence by Hutus against Tutsis when the Hutus came into power in Rwanda.   

so they can differentiate themselves from others as they saw themselves as the superior race. the star was basically a symbol that meant you are a less of a person than i am because of my race. the star was also degrading for those who had to wear it because they were aware of this and the nazis used the notion to make them feel less like a person.