ABSTRACT Although one extreme is more desirable than the opposite extreme on most trait dimensions, neither extreme reflects the most favorable level of the trait. Rather, extreme trait levels are usually considered to be less than optimal. Using a round-robin design, 76 groups of 4 persons each described themselves and each other on 30 trait dimensions and indicated the optimal level on each dimension. Moreover, personality inventories and measures of socially desirable responding were administered to the participants for self- and peer descriptions. Associations between trait level and trait level desirability comprised linear as well as curvilinear components. Participants preferred the optimal level in describing themselves, but trait levels beyond the optimal level in describing peers. A new measure of self-enhancement bias is suggested.