The current study examined the effect of a group's potential for improvement and decline in morality and competence on applicants' willingness to join the group. We conducted four experiments with 399 Chinese participants who rated their willingness to join groups with potential for improvement, potential for decline, or stability in terms of morality or competence. The results showed that, compared with groups with stable competence, participants preferred groups with potential for competence improvement and were more averse to groups with potential for competence decline. However, the biases regarding the potential for moral improvement and decline were asymmetric. Specifically, compared with groups with stable morality, participants had no preference for groups with potential for moral improvement, but were more averse to groups with potential for moral decline. Possible explanations for the asymmetric biases regarding the potential for moral improvement and decline and future research directions are discussed.