This paper investigates whether the effect of education on social tolerance is consistently positive across different time periods. Since the number of students in higher education has been increasing for the past decades in the U.S., the effect of education on social tolerance may have changed. Using the data from General Social Survey (GSS) 1977 ~ 2012 and hierarchical age-period-cohort models, the results of this study show that: (1) people with more education express more social tolerance for homosexuality and homosexual acceptance; (2) the effect of education on social tolerance for homosexuality has been continuously increasing over time; and (3) the effect of education on social tolerance for homosexual acceptance is small, but is still positive over time periods. People in the U.S. have become more tolerant of homosexuality and homosexual acceptance, and younger generations have been shown to be more open to homosexual acceptance and more tolerant than older generations. Liberal religious and political views are positively associated with homosexuality and homosexual acceptance. Finally, using a Monte Carlo simulation and a comparison between the simulation and OLS results, this paper also finds that social desirability bias influences individuals' social tolerance for homosexuality and homosexual acceptance. Social desirability bias decreases the estimate of education on homosexuality and homosexual acceptance.