*Note for the reader: When I say “personality” I am referring to the Big 5 personality framework, described in this post.
In general, would you say you are more extraverted (outgoing, enjoy social settings) or introverted (reserved, enjoy lower stimulation settings)? Can you think of a time when you were more extraverted than usual? Maybe a time when you were seeing your favorite band with your best friends. More introverted? Maybe you went along to your spouse’s high school reunion (these are, of course, illustrative examples which are not at all reflective of the author’s own experiences…)
States vs. traits
The eagle-eyed reader might have noticed that my initial prompt asked how extraverted/introverted you are in general, whereas my examples of times when your personality might have shifted a bit were specific situations. Personality tends to be thought of as a static trait that acts upon different situations (e.g., extraverts walk into a club and immediately look for the dance floor while the introverts look for an unoccupied corner.) In reality, it seems that your general disposition (i.e., your trait) and situational demands tug on each other. Maybe “your song” comes on at the club, so you move furtively to an inconspicuous region of the dance floor to bob your head and self-consciously sway a few inches in either direction. You still lean heavily towards introversion (your trait), but the situation has nudged you a little bit towards extraversion in this particular moment (your state).
The psychological term for the variation in personality within individuals across multiple observations is intra-individual variability. (The variation from person-to-person is inter-individual variability — makes sense!) Whole trait theory seeks to reconcile the general stability of personality with the situational variability that has been observed (it is by no means the only theory, but a full review of personality theory goes way beyond this post.) It posits that traits are essentially made up of a distribution of states, which are formed over time across a variety of situations (see Figure 1 below.) What determines a state is how a person interprets a situation, their current motivations, their genetic/biological/habitual tendencies, and influences of past events on present behavior (along with a bit of randomness thrown in.) Consider your personality when participating in the first meeting at your new job. Maybe in most situations, you’re pretty extraverted, but you reason that this is a situation that requires more listening and less talking (interpreting the situation). You are also motivated to make a good initial impression, in this case, by demonstrating your thoughtfulness and respect for those with more experience. Of course, these will be tempered by your disposition towards making small talk before the meeting starts.
Figure 1. Each dot represents any given situation in time. I’ve color coded 3 different types of situations (at work, at home, with friends) to demonstrate how personality might interact with environment. With friends, they’re more extraverted and at work — more introverted. At home, they’re pretty spot on with their overall average. If you think about it, your personality at home is probably best aligned with your overall trait personality, because you have more control over that environment! The extravert’s home will have a great space for hosting the monthly book club whereas the introvert will have a nice cozy reading nook.
How do we know intra-individual variability exists?
Psychologists have taken several approaches to measuring intra-individual variability (each with its own strengths and weaknesses.)
Ecological momentary assessment - psychologists measure personality repeatedly over time (this often means a person gets texted a survey at particular intervals as they are going about their day.)
Contextualized personality measures - people are asked to rate their personality while imagining themselves in specific contexts (at work or at home.)
Assessing item variability for a trait - a personality score for a trait like extraversion is made up of the average of many items that get at different facets of the trait (e.g., “I see myself as someone who is talkative.” and “I am an active and vigorous person.“ are both facets of extraversion.) One way to examine intra-individual variability is to see how much someone varies from item-to-item.
Some people vary more, others less
One’s tendency to vary from moment-to-moment is pretty stable (and consistent across personality traits), which means that the variability of one’s personality could be considered a trait in and of itself (for a deeper discussion, see this review by Emorie Beck and Joshua Jackson)! In other words, Eleanor might be very extroverted in general (trait extroversion), but also jumps from super extrovert to super introvert depending on the situation. Chidi, on the other hand, could be an introvert who is pretty much always looking for the nearest chair he can go sit in to open up a nice book and avoid talking to people. So Eleanor could be considered an “high variation” extravert whereas Chidi is a “low variation” introvert.
Figure 2. Some folks are more sensitive to their environment than others. (Did you catch the references? There are 3 of them in this figure — one is super obvious if you know the show, one is a little tricky, and I think the third is pretty difficult.)
Can people judge their own moment-to-moment personality?
A study by Jessie Sun and Simine Vazire sought to understand people’s accuracy at judging their state personality in real-world situations. They equipped participants with a wearable audio recorder and completed self-reports of their personality states four times a day. They then had observers who listened to recorded activity during these times and also rated them on personality states (it’s worth noting, the participants went through the recordings first and deleted anything they didn’t want others to hear.) So in this case, observer ratings acted as the criteria for participants’ “actual” states.
Agreement between participants and observers was high for extraversion and conscientiousness, but not for neuroticism or agreeableness. This means people are able to notice moment-to-moment fluctuations for extraversion and agreeableness. For neuroticism, the authors argued that the internal nature of this trait likely made it difficult for observers to rate, suggesting that it isn’t the participants, but the observers who have trouble here. However, for agreeableness (which, like extraversion and conscientiousness) is associated with more outward behaviors, they concluded that participants were simply less sensitive to their fluctuations. So, you may be pretty attuned to how industrious and social you’re feeling, but when it comes to whether you’re being kind of a jerk, you might want to trust the people around you.
Why this matters for how you interact with others.
What have we learned? From a 1,000 foot view, personality is stable. But when you break that down into each moment in life, the qualities a person might be expressing will shift around depending on environmental factors (put succinctly, personality is both a trait and a state.)
Err towards uncertainty
I think this is important to know when it comes to how we interact with and think about other people. Humans excel at caricaturization, which can lead to inflexible and incomplete beliefs regarding others’ likes/dislikes, and how a person might behave in certain situations. In the words of author and activist John Green, we should strive to “imagine others complexly”. Given the computational limits on our imagination, I will add that we should also err towards uncertainty. Yes, our simplified schemas of people may be accurate more often than not, but if we fail to leave room to be surprised, at a minimum we will end up missing out on unexpected, wonderful experiences, and at worst we may end up hurting those around us.
Erring towards uncertainty can also be applied to how we think about our own personalities. There are lots of personality inventories out there (like the MBTI and Enneagram) that have a complex array of types and subtypes, but at the end of the day, they pin you down to a type (watch this for more discussion on how not to measure personality.) Continuous personality inventories like the Big-5 allow for movement along a spectrum (and allows for traits which lie in the middle — the so-called “ambivert”.) I sometimes wonder if the typology personality inventories like the MBTI force us into a box, limiting our potential for intra-individual variability.
Finally, when it comes to judging other’s personality states, you may be fairly accurate when it comes to judging your own (and others’) extraversion and conscientiousness in-the-moment, but you are less likely to notice peoples’ internal struggles, so lead with compassion. As far as how you are treating those around you — keep in mind that they are likely to be a better judge of that than you are.