The older, lower results, which are even lower than estimated in the general population, were due to the methodology of questioning respondents face-to-face, which led to social desirability bias.[43][50] In contrast, one comparative study from 1974 and 1980 showed 7.5% of sampled students at University of Northern Iowa reporting zoophilia,[51] while other studies find only 2.2%[52] to 5.3%[53] expressing fantasies of sex with animals.