Reading focus
Syllabus: How Stable Is Personality?
Keep separate a changing average, a changing rank, and a changing individual trajectory.
Why you’re reading it. Establish the distinctions needed to interpret every later claim about personality development.
A question to consider. Alex and the rest of the team all become more organized after joining the company. Which kind of change does that describe, and what would establish whether Alex’s relative standing changed?
Why this reading
An answer to whether personality changes depends on what kind of change is being considered. This short review defines several kinds of stability before focusing on changes in a group’s average and differences in individual trajectories. It provides a vocabulary for evaluating claims that can otherwise sound contradictory.
Before you read
A trait describes a relatively enduring tendency, not behavior that occurs on every occasion. Mean-level change concerns a group’s average; rank-order stability concerns people’s relative positions. Two people can both become more conscientious while retaining the same ordering. Cross-sectional studies compare people of different ages; longitudinal studies follow the same people over time.
Read for
- Keep the different meanings of change separate when interpreting the evidence.
- Distinguish average age-related patterns from variation in individual trajectories.
- Identify where the review moves from describing change to proposing explanations involving adult roles and experiences.
Consider afterwards
- A cohort’s average conscientiousness rises while its rank-order correlation remains high. What changed, what persisted, and what would you still need to know about any one person?
Editorial context
This is an overview of evidence available in 2008, not a current set of universal age norms. The later Bleidorn and colleagues meta-analysis revisits the size and timing of stability and change with a larger evidence base. Associations between adult roles and trait changes do not, by themselves, establish that taking on a role caused the change.