Faculty voice: Three myths about personalities

March 20, 2024 - Shelly DeJong

 A headshot of Ted SchwabaTed Schwaba, Ph.D. is an assistant professor in Michigan State’s Department of Psychology in the research area of Social/Personality.  

People have evolved to be good at judging personalities. As a species, it's extremely important to know if someone else is dangerous or untrustworthy. We also have a lot of experience evaluating the personalities of others because we come into contact with so many people. Most of the time our impressions about personality are spot on, which is good. It would be horrible if scientists discovered that everything that humans think about themselves is wrong! 

Even still, there are times when we think the world works one way, but research says otherwise. Here are three myths that you may assume to be true about personalities, but current findings robustly refute. 

Myth #1: Birds of a feather flock together in friendships and relationships. 

The way that we think about the world is that similar people tend to spend time together. Stereotypically, we think of tough guys hanging out together while nerds spend time with each other. In reality, there's very weak evidence of assortative mating or the tendency for people to choose mates with similar personality traits. What this means is that if I know who you are as a person, I cannot predict what your partner’s personality will be like. This is not true across the board: there is quite a bit of assortative mating for qualities like education level, religion, and political beliefs. But in terms of personality, there's very little matching.  

This also applies to friendship, and you can likely see this in your own life. Look at who you are friends with. An extraverted person is going to be friends with everybody, not just other extraverted people. Conversely, an introverted person is not going to have as many friends, but the people who they are friends with will be some extraverts and some introverts. The same goes for people who are organized and people who are friendly or unfriendly.  

You really can be friends with anybody.  

Myth #2: At a certain age, your personality becomes fixed.  

Many adults seem pretty set in who they are. Change is very visible when you’re younger and maturing. For example, a five-year-old isn’t going to be very responsible. A 30-year-old (hopefully) is. Research shows, though, that people can change and do change throughout their whole lifespans. So, that responsible 30-year-old may be more or less responsible when they are 70 years old, too. 

Earlier personality researchers claimed that personalities were set like plaster by the age of 30. But that isn’t true. Researchers today administer surveys to people at multiple points in their life and you can see that they are still changing well into their 80s. And this goes for all kinds of personality traits. Traits like optimism might seem like obvious candidates for change depending on your life circumstances. But even deeper trait-level characteristics, like how responsible we are or how friendly we are, can and do change.  

One takeaway is that if you’re not happy with your current personality, you’re not stuck where you are. You’re not going to wake up tomorrow and be a whole different person, but there is quite a bit of wiggle room in your personality.  

Myth #3: We are powerless to change our personality traits. 

We are not powerless to change our personality traits, but it's not so easy. There’s a self-help myth that if you read a book and do just one little thing, you’ll change who you are forever. If it were that easy, personality wouldn’t work as a concept, because people would be so malleable as to make trait attributions like “he’s careful” and “they’re adventurous” useless. There is new evidence coming out, though, that people can change their personalities through hard work, effort, and sticking to targeted plans for change.  

Traditionally one thinks of therapy as a way to address or alleviate mental health symptoms that are causing you difficulty. However, some studies have also looked at people's personality traits before and after therapeutic experience or before and after they take antidepressant medications. Those studies have found changes in personality traits. For example, therapy may be helpful to treat your depression, but in the process, you're also changing your trait levels of negative emotionality more generally. Most people want to change their personalities, so this is potentially quite important. 

There's also some research that shows that college students tend to change their personality traits in the direction that they want, over time. So, if a student wants to be more friendly, they generally do tend to become friendlier over time. Another group of researchers recently tested a smartphone app that targeted interventions for specific personality traits. If a participant said they wanted to be more extraverted, they’d then receive extraversion challenges to complete, like saying hello to a stranger or striking up a conversation with a barista at a cafe. Those that picked a certain trait to change and completed the challenges, tended to show lasting change even one year after the intervention ended. Close others also reported seeing this change in them. That’s important to note because so much of changing who you are is in your head – it’s seeing the world in a different way. But if a romantic partner or close friend is also noticing the change, you can be much more confident in the reality of that change in terms of observable characteristics like behavior.  

One thing I love about being a social/personality psychologist is that new research continues to refine our understanding of the world. If you asked personality psychologists in the 1980s, they would have said that people’s personalities don’t change after they are 30 years old. Now not only do we know that personality does change across the lifespan, but evidence is beginning to show that we can help people change their personality traits in the ways they want to. In the next couple of decades, I’m looking forward to seeing how our understanding of personality continues to evolve, especially in terms of debunking myths we currently believe are true.  

Learn more about the Social/Personality research happening at Michigan State here.