The idea that personality never changes once you reach adulthood continues to be challenged by study after study. There’s one big problem, however, even with the most sophisticated study, they use the wrong measure of personality.
The well-known Five Factor Model, or Big Five, with its scales that measure neuroticism, openness, extraversion, conscientiousness, and agreeableness, wasn’t designed for anything other than one-time, stable measurements. Eventually, though, researchers began to give it on repeated occasions, anywhere from months to years apart. What emerged were findings that showed people did, in fact, change over time, throwing into disarray the previous assumptions about personality traits as so-called “enduring dispositions.”
Personality as a State, not a Trait
In a new study by University of Basel’s Fabian Gander and colleagues (2025), the lack of validated measures to study momentary changes in personality created “potentially biased findings” (p. 2). What’s more, Gander and colleagues believe that traits are no more than collections of “states,” or fluctuations in emotions, behaviors, and thoughts.
Think about your own personality. Maybe you’re feeling pretty calm and centered today, so if someone gave you a neuroticism measure, you’d come out smelling like a rose. What about yesterday, though? Did you experience frustrations come your way? Did this make you focus on your flaws? If you had to answer a typical neuroticism scale item, you’d be faced with making general ratings about how you “usually” are. Obviously, whether it was yesterday or today, you’d be making a leap of faith as you tried to estimate your personality as a stable entity.
The 15-Item Personality State Scale
The Swiss research team decided to build on a previous adjective-based rating measure that could cover all five factor traits, but which they thought was too long (30 items) to make it practical for personality state assessment. They tested this new measure across two studies, first identifying which items would meet the necessary statistical criteria for sound measurement, and then correlating the resulting scale with other measures of mood. In their second study, 1,725 participants aged 18 to 40 completed the new measure across seven testing occasions.
Satisfied with their analyses, Gander and colleagues have now made the scale available. Test yourself on these 15 items by rating where you stand on each pair.
- Easy-going/nervous
- Carefree/depressed
- Irritated/balanced
- Shy/sociable
- Assertive/reserved
- Active/passive
- Cold-/warm-hearted
- Unfriendly/friendly
- Good-natured/suspicious
- Disorganized/organized
- Inefficient/efficient
- Unreliable/reliable
- Artistic/unartistic
- Uninterested/curious
- Full of ideas/lacking ideas
The order of five-factor qualities represented by these items is as follows (three per quality): neuroticism, extraversion, agreeableness, conscientiousness, and openness. As a thought experiment, rate how you would have answered these yesterday or maybe a week ago. How did things change? What you can also learn is that no day is ever all good or all bad in terms of personality. You could feel both high on neuroticism and openness or vice versa on any given day.
There was one intriguing result, though, with respect to neuroticism in particular. People higher in this quality tended to show more fluctuations in mood. There were also swings in extraversion and openness, suggesting possibly greater “behavioral flexibility.” The highly conscientious, perhaps predictably, didn’t show that much fluctuation, supporting the idea that it’s possible to be “too” conscientious.
The Value of Knowing Your State
Armed with the knowledge that personality is more than a hard-wired set of tendencies, you can now take that quick 15-item scale and try it out on yourself as you go about your daily life.
Minimally, you can feel some relief in knowing that you’re not stuck with being anxious just because you’re having a bad day or a bad set of days. It’s too easy for personality to become a set of self-fulfilling prophecies rather than to see your qualities as reflective of your daily situations. As the song says, “don’t give up on yourself.”
To sum up, there’s value in viewing personality as ever-changing and an even adaptive ability to fluctuate along with life’s challenges. What’s anxiety-producing today may turn out to be a source of contentment and balance tomorrow.
