Personality Trait Development in Adulthood

Abstract

Personality traits refer to relatively enduring, automatic patterns of thinking, feeling, and behaving that distinguish one person from another that are evoked in trait-relevant contexts. Contemporary research has shown that personality traits are both consistent over time and yet change systematically in adulthood. In this chapter, we review the different ways that researchers conceptualize and assess personality trait stability and change. We summarize accumulated evidence pointing to at least moderate sized test-retest coefficients for personality traits across all phases of the life span and highlight the robust pattern of increasing rank-order consistency with age. We describe the consistent findings for mean-level changes in personality such that, on average, individuals tend to become more confident, warm, responsible, and emotionally stable as they grow older. Although mean-level changes are evident across the life span, the young adult years seem to be a particularly active time in the life span for mean-level changes in personality traits. We then note that different individuals may change to a greater or lesser extent than is captured by these mean-level trends thereby pointing to the importance individual differences in change. After describing the evidence for different forms of stability and change, we identify the mechanisms that may explain personality continuity and personality change. We discuss four processes of attraction, selection, manipulation, and attrition that promote consistency as well as the transformative processes that may explain how personality changes occur. Last, we describe the theoretical and practical implications of personality development research with an eye toward social policies to improve lives.