Are Social Expectations a Possible Mechanism for Adult Personality Change: Empirical Evidence for Social Investment Theory

Abstract

Objective: Personality traits change in both mean levels and variance across the life span but the mechanisms underlying these developmental trends remain unclear. Social investment theory is one of the leading theories trying to explain personality maturation, suggesting that social role expectations drive personality changes in adulthood. However, there is not sufficient empirical evidence for SIT, thus the present study tested whether social expectations can explain personality maturation in young adulthood. Methods: A pool of 257 personality items, which was not driven by a priori conceptual model of personality, was used to measure young adults’ personality trait mean levels, personality variance and socially expected level of traits from different perspectives (friends, partners and bosses/supervisors). Results: There were consistent expectations for how young adults should think, feel and behave. Personality traits under stronger social expectations have higher mean levels and lower variances than traits under lower expectations; traits with stronger social expectations show higher means at later ages; and traits’ variances increase with age. Conclusion: Our results are partially consistent with SIT, suggesting that social expectations could be a potential mechanism to explain personality changes in young adulthood.