Erikson's psychosocial developmental theory assumes that valence of one's identity (i.e., identity content valence) defined by positive and negative identity elements is important for understanding patterns of (mal)adaptation. However, previous empirical research on identity and (mal)adaptation has focused on how individuals deal with identity issues (e.g., exploration and commitment), while neglecting identity content valences. In contrast, this study assessed identity content valences in terms of positive and negative identity elements. Theoretically, identity content valences affect (mal)adaptation, whereas individuals' (mal)adaptation influences their identities. Consequently, this study examined reciprocal relationships between identity content valences and adaptation (i.e., prosocial behaviors) and maladaptation (e.g., externalizing symptoms) in a sample of Japanese young adults, including socioculturally relevant indicators of maladaptation (i.e., hikikomori symptoms and suicidal ideation). This study includes 2,313 Japanese young adults who participated in a three-wave longitudinal study. The cross-lagged panel model and random intercept cross-lagged panel model revealed reciprocal relationships between identity content valences and (mal)adaptation at the between-person level. Negative identity elements positively predicted suicidal ideation. Meanwhile, prosocial behaviors positively predicted positive identity elements, whereas hikikomori symptoms and suicidal ideation positively predicted negative identity elements. These relationships were significant only for socioculturally relevant indicators, suggesting the importance of considering sociocultural contexts.
Keywords: Japan; adaptive functioning; identity content valences; longitudinal; maladaptive functioning.