By the time he began classes at Harvard, Zuckerberg had already achieved a "reputation as a programming prodigy", notes Vargas. He studied psychology and computer science as well as belonging to Alpha Epsilon Pi, a Jewish fraternity, and Kirkland House.[2][9][26] In his sophomore year, he wrote a program he called CourseMatch, which allowed users to make class selection decisions based on the choices of other students and also to help them form study groups. A short time later, he created a different program he initially called Facemash that let students select the best looking person from a choice of photos. According to Zuckerberg's roommate at the time, Arie Hasit, "he built the site for fun".