This paper explores whether social desirability affects theillusion of explanatory depth (IEOD) by comparing themagnitude of this illusion in topics with different levels ofsocial desirability within several domains. This question waschosen because prior literature shows that social expectationsabout how much a person should know about a certain topicaffect the magnitude of the IOED. Previous research showsalso that social desirability has an effect on a similar illusionrelated to argumentation, and that the IOED is affected by theway a person thinks knowledge is distributed in his or hersocial group. In order to do so, 184 participants were assignedrandomly to three knowledge domains (history, economics,and devices) and in each domain they rated theirunderstanding of a high-desirability and a low-desirabilitytopic following a standard IOED procedure. Results show thatsocial desirability has an effect on the IOED magnitude andthat overestimation of understanding varies among domains.Particularly, participants tend to overestimate theirunderstanding of high desirability topics only. This effect wasstronger in the historical domain.