What do we know about personality change?
There are different kinds of change.
Rank order change refers to how much the ordering of people on a trait at one assessment differs from the ordering of the same people when assessed a second time. Personality traits tend to have fairly high rank order stability in adults. This means that if you are more extraverted or open than someone else today, odds are you still will be a decade from now. However, there is also evidence that rank-order stability is highest during middle adulthood.
Mean-level change indicates how average level of a personality trait in a group differs across two assessments. Research on mean-level change suggests that people usually mature between adolescence and adulthood. This is evidenced by decreased neuroticism, increased agreeableness, and increased conscientiousness during that period. Mean-level changes during other parts of the lifespan seem to be more subtle.
Profile change refers to how the configuration of traits within a person changes over time. This is the only type of change that applies to individuals, without reference to others. There is relatively little research on this type of change.
Individual-level change means how much individual people differ from these mean-level trends. There are fewer studies on this type of stability, but data indicate that many people tend to stray from the average trajectory. For example, some people don’t show the same increases in adaptive traits during the transition to adulthood. This observation leads to a central question for the PCC - what might be happening in those peoples’ lives that causes them to differ from others?
Both genetic and environmental factors are associated with personality and personality change.
Longitudinal twin studies have shown that monozygotic twins tend to be more similar and tend to change in more similar ways than dizygotic twins. This is strong evidence that heritable factors explain some of the individual differences in personality and personality change. However, this research has also shown that environmental factors that are not shared among twins also reliably influence both personality trait levels and enduring changes in personality, leading to greater dissimilarity in genetically identical twins across the lifespan. This suggests that aspects of the environment cumulatively shape the course of personality - the PCC is motivated to figure out what these factors are.
Personality is related to important life outcomes.
There is a very large body of research showing that personality traits predict important life outcomes like health, relationship satisfaction, psychopathology, and work performance both cross-sectionally and longitudinally. There is a smaller but emerging body of evidence that changes in personality traits are related to changes in these important outcomes. This suggests the potential for personality change interventions to improve lives. Thus, a better understanding of the factors that influence personality changes could have important implications for public policy and individual well-being. The PCC hopes to identify connections between personality change and important life outcomes and work to leverage evidence about personality change for public good.
The overall goal of the PCC is to build on the things we know to begin figuring out some of the things we do not know. Here are some of those things.
What is the relevance of personality change for public policy?
How does personality drive important life outcomes? What is the impact of culture, nationality, and language on personality and personality change? How and to what extent can personality be changed purposefully to improve individual well-being and social harmony? In what cases is it actually better not to intervene, but rather to let natural personality changes run their course? Not everyone wants to have the same levels of different traits, or to change traits in the same direction - how and to what extent can personality change models be individualized?
What are the sources of personality change?
What specific long-term and short-term factors affect personality change? How do genetic and environmental sources interact and transact so as to impact personality? Are there critical developmental periods for different sources of personality change? To what extent does person-environment fit matter for individual and societal adaptation?
What are the processes underlying personality change?
What are the specific processes by which the environment shapes personality change? How can perception, behavior, affect, motives, and cognition be distinguished so as to theorize about and study these processes? Do habitual microprocesses build up to enduring trait changes? What are the specific mechanisms by which processes and traits are related to one another?
How can we advance our methods to more effectively study personality change?
How should personality change be measured? How sensitive are different assessment methods to personality change? What should we measure to identify the environmental sources of personality change? To what degree do existing measures generalize to other cultures, nations, and languages? To what degree do personality change processes that apply to people in general apply to individuals in particular?
There are different kinds of change.
Rank order change refers to how much the ordering of people on a trait at one assessment differs from the ordering of the same people when assessed a second time. Personality traits tend to have fairly high rank order stability in adults. This means that if you are more extraverted or open than someone else today, odds are you still will be a decade from now. However, there is also evidence that rank-order stability is highest during middle adulthood.
Mean-level change indicates how average level of a personality trait in a group differs across two assessments. Research on mean-level change suggests that people usually mature between adolescence and adulthood. This is evidenced by decreased neuroticism, increased agreeableness, and increased conscientiousness during that period. Mean-level changes during other parts of the lifespan seem to be more subtle.
Profile change refers to how the configuration of traits within a person changes over time. This is the only type of change that applies to individuals, without reference to others. There is relatively little research on this type of change.
Individual-level change means how much individual people differ from these mean-level trends. There are fewer studies on this type of stability, but data indicate that many people tend to stray from the average trajectory. For example, some people don’t show the same increases in adaptive traits during the transition to adulthood. This observation leads to a central question for the PCC - what might be happening in those peoples’ lives that causes them to differ from others?
Both genetic and environmental factors are associated with personality and personality change.
Longitudinal twin studies have shown that monozygotic twins tend to be more similar and tend to change in more similar ways than dizygotic twins. This is strong evidence that heritable factors explain some of the individual differences in personality and personality change. However, this research has also shown that environmental factors that are not shared among twins also reliably influence both personality trait levels and enduring changes in personality, leading to greater dissimilarity in genetically identical twins across the lifespan. This suggests that aspects of the environment cumulatively shape the course of personality - the PCC is motivated to figure out what these factors are.
Personality is related to important life outcomes.
There is a very large body of research showing that personality traits predict important life outcomes like health, relationship satisfaction, psychopathology, and work performance both cross-sectionally and longitudinally. There is a smaller but emerging body of evidence that changes in personality traits are related to changes in these important outcomes. This suggests the potential for personality change interventions to improve lives. Thus, a better understanding of the factors that influence personality changes could have important implications for public policy and individual well-being. The PCC hopes to identify connections between personality change and important life outcomes and work to leverage evidence about personality change for public good.
The overall goal of the PCC is to build on the things we know to begin figuring out some of the things we do not know. Here are some of those things.
What is the relevance of personality change for public policy?
How does personality drive important life outcomes? What is the impact of culture, nationality, and language on personality and personality change? How and to what extent can personality be changed purposefully to improve individual well-being and social harmony? In what cases is it actually better not to intervene, but rather to let natural personality changes run their course? Not everyone wants to have the same levels of different traits, or to change traits in the same direction - how and to what extent can personality change models be individualized?
What are the sources of personality change?
What specific long-term and short-term factors affect personality change? How do genetic and environmental sources interact and transact so as to impact personality? Are there critical developmental periods for different sources of personality change? To what extent does person-environment fit matter for individual and societal adaptation?
What are the processes underlying personality change?
What are the specific processes by which the environment shapes personality change? How can perception, behavior, affect, motives, and cognition be distinguished so as to theorize about and study these processes? Do habitual microprocesses build up to enduring trait changes? What are the specific mechanisms by which processes and traits are related to one another?
How can we advance our methods to more effectively study personality change?
How should personality change be measured? How sensitive are different assessment methods to personality change? What should we measure to identify the environmental sources of personality change? To what degree do existing measures generalize to other cultures, nations, and languages? To what degree do personality change processes that apply to people in general apply to individuals in particular?