Whitepaper
Is Personality Set In Stone? Myths, Facts and Data on How Personality Develops Over Time
An accurate personality profile holds strategic value for recruitment and development. But does that profile remain valid over time? Can people reshape deeper personality traits, or do the patterns stay relatively stable?
This whitepaper draws on OPTO personality test data and current research to explore personality's true nature: which traits remain stable, where the potential for development lies across generations, and how organisations can apply this knowledge.
Here's what you'll get from this whitepaper:
- The Big Five model and the OPTO personality test: how personality is measured on a scientific basis.
- Five catalysts that drive real personality change, from intentional effort to major life events.
- A generational breakdown of how personality traits shift from adolescence to late adulthood.
- Why seniors can still develop, and what it takes to support that development.
What Are Personality Traits?
Personality traits are relatively stable ways in which we think, feel and behave, shaping how we perceive situations, respond to them, and what motivates us. As Chief Psychologist Lise Sustmann Allen puts it, personality traits are the ways in which we engage with the world, and they shape our intuitive and preferred behaviours. Two people can experience the exact same circumstances completely differently, purely based on personality, the same way one person's motivation for running a marathon might be community, while another's is competition or personal achievement. Personality traits are relatively stable, but not static: they don't change from one day to the next, but they can gradually develop over time through life experience, environmental influences and conscious choices.
What Is a Personality Profile?
A personality profile works a bit like a home survey: it gives an accurate snapshot at a specific point in time, while still recognising the potential for development. Just as a property can change through renovation, personality develops gradually through experience and intentional effort. The profile simplifies complex information to make it actionable, while still only representing one perspective on a person.
How Is Personality Understood in Psychology?
Two perspectives shape how psychology understands personality. Social constructivism and humanism approach personality from different angles, and both help explain why measurement is possible at all.
Social Constructivism
This perspective views personality as something that emerges through social relationships and interactions. Personality becomes dynamic and shaped by context, and people may show up differently at work, at home, or with friends, because personality is understood relationally rather than as something fixed.
Humanism
This approach identifies an inner core of fundamental traits that stays relatively stable over time. The environment influences personality, but this core persists, so people carry different "versions" of themselves where outward expression changes while the underlying personality remains consistent. This is the foundation that makes meaningful personality measurement possible.
How Do We Measure Personality?
Research consistently points to two tools as the most robust and widely used way to measure personality on a scientific basis.
The Big Five Model
Rather than being derived from a single theory, the Big Five emerged from extensive statistical analysis of how people describe themselves and others, identifying five broad traits with underlying facets. As Sustmann Allen puts it, when we measure personality, the Big Five is the most scientific way to do it.
OPTO Personality Test
Built on the Big Five model, OPTO applies across organisational levels for adult populations, regardless of industry, background or ethnicity, and measures 20 aspects across eight dimensions: Influence, Resilience, Cooperation, Efficiency, Delivery, Compliance, Agility and Innovation. This dataset makes it possible to identify, on an empirical basis, which traits stay stable and which respond to experience, context and development.
What Creates Real Change in Personality?
Personality change develops gradually, through several interacting factors. The overall principle is that change emerges through an ongoing interaction between existing traits and outside influences.
1. Intentional Effort and Goal-Setting
Active development and ownership increase the likelihood of lasting change.
2. Environment and Relationships
Workplace culture, social relationships and surroundings continuously influence behaviour and personality.
3. Coaching and Structured Development Programmes
Targeted initiatives foster reflection, introduce new perspectives, and support lasting behavioural change.
4. Major Life Events
Job changes, crises and significant transitions act as catalysts for personal development.
5. Repeated Behaviour Over Time
Small, consistent behavioural changes gradually reshape thoughts, emotions and patterns.
Personality Over Time: From Adolescence to Late Adulthood
Adolescence (10-19 years)
Statistical increases appear in social vitality and openness to experience, both of which decline again after age 60.
Early Adulthood (20-40 years)
Increases appear in social dominance, conscientiousness and emotional stability, reflecting the maturity that comes with adult responsibilities.
Middle Adulthood (40-60 years)
Conscientiousness and agreeableness continue to increase, emotional stability stabilises, and openness shows minimal change from early adulthood.
Late Adulthood (60+ years)
Statistical declines appear in social vitality and openness, alongside increased agreeableness, indicating greater social withdrawal and cognitive conservatism. Traits such as stress management, goal orientation, intellect, sincerity and suitability show higher development potential, while traits such as communication, self-confidence, assertiveness and structure tend to be more stable.
Can Seniors Still Develop?
A common misconception holds that age firmly sets personality traits, making change difficult, and that motivation to develop declines with time. Research contradicts both: personality continues to develop throughout life, including in later adulthood, though development may look different than in younger years.
1. Understand Individual Motivation
Motivation changes over time and is key to successful development.
2. Create the Right Conditions
Supportive environments and meaningful responsibilities increase the likelihood of behavioural change.
3. Actively Support the Process
Dialogue, feedback and targeted initiatives remain important, also for experienced employees. Development doesn't stop with age, it requires adapting your approach to the individual's life stage.