Does your personality influence what you do with your life and the decisions you make, or do life events and decisions influence your personality?

It’s now generally accepted that the environment plays a role in personality development, especially over the course of one’s formative years. But how? What factors steer an individual in one direction or another? How do life events, especially in early adulthood, shape an individual’s lasting personality?

A study conducted in Finland looked at personality trait changes among Finnish young adults. What the researchers wanted to know was, how did particular life events, as well as decisions made in young adulthood, affect measures of personality later on in life? 

At the heart of this pursuit is really the desire to know: how plastic is personality? Are Big Five personality traits fixed, or are we changing throughout the life cycle based on life events and transitions? Can you be on one personality “track” during childhood and then on a different one in adulthood, all because of life circumstances? 

Studying the Link between Personality and Life Events

Researchers looked at transitions, conditions, institutions and decisions, considered both normative and non-normative, to measure their impact on the individual’s personality during his or her early twenties. These events included:

  • Being in a relationship
  • Going to college
  • Having a job
  • Having a chronic health problem (e.g., diabetes)
  • Using illegal drugs

Researchers assessed the participants and their personalities at the beginning of the study (age 20) and again at the age of 23. At both stages participants were asked to comment on the above life events. Had they decided to study at a university, or at a technical school? Had they been in a relationship, had a job or tried drugs? Researchers then measured changes in each of the Big Five dimensions of personality and compared these results with the events experienced by each individual participant. 

What They Found

While change was noted in each of the dimensions of personality over the course of the study, the most significant relationships between life events and personality change pertained to conscientiousness and neuroticism. 

  • Getting a job correlated with a rise in Conscientiousness
  • Beginning a relationship also correlated with a rise in Conscientiousness
  • Studying in university correlated with a rise in Conscientiousness
  • Trying drugs correlated with a rise in Neuroticism
  • Onset of chronic disease correlated with a rise in both Neuroticism and Conscientiousness

Does Personality Determine Life Events, or Vice Versa?

In a lot of ways, trying to untangle this question of what influences what, is like asking: Which came first, the chicken or the egg? Does being conscientious land you the good, responsible job or does taking the job make you more conscientious and responsible? Do you take drugs because you’re neurotic or does high neuroticism tend to lead to drug use? Is it the same at all stages of life?

After showing that these life events do indeed impact personality development in young adulthood, and in some cases even alter it, researchers wanted to know why. Why would having a job or being in a romantic relationship, for example, increase conscientiousness?

The researchers suggest that new life roles create a sort of positive feedback loop. “These results suggest that the roles we enter that require new types of behavior modify our self-view, even when such roles are forced upon us rather than chosen,”1 and that this will have an impact on personality over the long term. We can see why this would happen. You engage in the required behaviors, you receive positive feedback, you persist in the behaviors over time, and the changes become fixed. In the case of positive events and personality traits, this builds confidence, you have less to worry about and this, in turn, may lead to greater emotional stability because you’re succeeding at life and things are generally working out. 

Nonetheless, researchers also note, “It is currently unclear why social investment or other life transitions and events relate to personality change.”2

Though they haven’t proved it, the results of this study and other anecdotal evidence do suggest that if a person desires to change their personality, it's worthwhile to invest time and effort towards this goal. The key is that if you want to change your personality, you will need to immerse yourself in the situations, circumstances and commitments that require the traits you desire. The older you are, the greater the challenge will be, though certainly not impossible.

Personality was once thought to be completely static—determined and solidified in early childhood. While people may shift slightly due to life events and the march of age, it was generally believed that, although we might seek self-improvement in various areas of life, our personalities were going to stay more or less fixed. 

That’s more or less true. However this research, as well as other studies being conducted around personality change, show that personality is a little more malleable than we thought (although large scale personality changes, especially later in life, can still be difficult). What we see is that personality, and the development of it, is more than a finite process that we complete before kindergarten. To some degree, our personalities continue to develop throughout the life cycle, though tapering off significantly after one’s early twenties. 

This study shows that life events taking place in late teens and early twenties can have a marked effect on one’s personality, and that the changes and/or developments tend to stick. The experiences that individuals have or don’t have in young adulthood may go a long way toward shaping the kind of people they will be as more mature adults. 

This means the early twenties may be a more important period of development than we thought. Parents and teachers, seeing how formative these years are, may be more proactive in encouraging students to engage in positive social roles, or to pursue the specific kinds of circumstances and events that lead to positive personality outcomes. 

Those efforts may also include helping young adults avoid the circumstances that tend to lead to lasting negative outcomes. For example, parents may be nonchalant about a child’s drug experimentation by the time he or she has reached the age of legal adulthood. However, the research shows that these years are still vital in the development of the individual’s personality.

As the study has shown, personality, even in young adulthood, is still a forming, developing and changing thing. The circumstances of our lives and the decisions we make are creating our personalities, even at later stages of development. 

“This highlights the usefulness of examining life events and transitions, as well as people’s perceptions of these events and transitions as moderators of personality change,” said the researchers in the study. 

“Future research on life events and personality transitions has at least two important challenges: separating changes that are due to life events from those that are due to maturation, and discovering the mechanisms through which life events affect our personalities.”3



Leikas, S & Salmela-Aro, K (2014). Personality Trait Changes Among Young Finns: The Role of Life Events and Transitions. Journal of Personality, 83, 1, 117-126
1, 2, 3 Leikas, S & Salmela-Aro, K (2014). Personality Trait Changes Among Young Finns: The Role of Life Events and Transitions. Journal of Personality, 83, 1, 117-126
Jacki Christopher
Jacki Christopher is a freelance writer based in Philadelphia with interests in personality and relationships, small business development and communications. She is an ENFJ.