In some instances, different religions have been known to promote heteronormative beliefs through their teachings. According to Sociology professors Samuel Perry and Kara Snawder from University of Oklahoma, multiple research studies in the past have shown that there can be and often is a link between the religious beliefs of Americans and homophobic behavior. Out of the world's five major religions Christianity, Judaism, and Islam all uphold heteronormative views on marriage. Some examples of this playing out in recent years include the incident involving Kentucky clerk Kim Davis, who refused to give marriage licenses to same-sex couples on the grounds that it violated her spiritual views, as well as the Supreme Court case which ruled that a Colorado baker did not have to provide a wedding cake for a gay couple based on his religion.