People include other people in their self-concept. Research has examined the causes and effects of including liked, but not disliked others into the self-concept. Liked others are included because of a motivation to affiliate and get closer to the other person. The current investigation examined whether disliked others are included as a result of a motivation to differentiate and distinguish oneself from the other person. It also examined how self-concept inclusion of disliked others affects self-concept clarity. First, I tested whether people include disliked others into their self-concepts by showing a memory bias for disliked others similar to that of liked others (Study 1). Liked others, but not disliked others or acquaintances, showed this memory bias. Next, I tested whether people were motivated to differentiate themselves from disliked others by measuring whether they had slower reaction times when characterizing the self with traits similar to those of disliked others (Study 2). I did not find this effect. Finally, neither study showed a mediating effect of self-concept clarity. These results failed to show support for the hypothesis that disliked others are included in the self-concept and that including others in the self affects self-concept clarity.