Personality change and workouts

If you want to get strong, you exert your muscles in a way that you want them to develop. Want to be able to lift a lot? Lift heavy weights a few times. Want to be able to lift for a long amount of time? Lift lighter weights many times. While this seems almost overly simplistic, the underlying response of your body is incredibly impressive: your biology gradually shifts to account for the new demands that your activity places upon it. Breaking down muscle tissue frequently sends a message to your body to rebuild that muscle tissue, and more strongly.

If you want to become friendly, what should you do? Exert your friendliness muscles, so that your brain rebuilds itself more friendly-ly? Potentially. Currently, personality change theory posits that biological change is a main pathway towards personality change (Roberts & Jackson, 2008). The classic example of this comes from Phineas Gage, a miner who took a steel rod through the noggin’ and turned into a hostile, cold person. Presumably, this was because areas of his brain responsible for aggression inhibition were damaged. So one easy way to mess with personality is to lobotomize people. Unfortunately, that’s probably not going to improve the traits that are considered socially desirable, it’s going to make things worse.

By coincidence or not, a basic tenet of exercise (work what you want to become strong) also applies to neurobiology (the neurons that fire together wire together). So, potentially, repeated or intense activation of neural circuitry implicated in friendliness can make a person more friendly. That’s cool! Here’s where we can begin using what we know about exercise to extrapolate theory about personality change.

First is that exercise benefits are contingent on accruing a critical mass of exercise. Running a single mile one time will not make a person healthy, and neither will performing a single act of kindness make a person’s baseline friendliness increase.

Second is that there are different ways to work the same muscles. Specificity can vary. Curls, the bench press, and pull ups all work biceps. Presumably, repeated practice of any activity that targets friendliness can make a person more friendly. However, it may be that intensely specific exercises are not able to trickle-up and affect people at the trait level. If you practice keeping a calendar, you may not see effects at the level of your entire conscientiousness trait (especially if the questionnaire doesn’t include any questions assessing keeping track of dates, such that real change in your latent conscinetiousness may not be picked up on, but that’s a whole nother issue).

Third is that there may be trait “steroids.” What limits improvement in strength training? One factor is that the body rebuilds itself slightly stronger each time muscles are worked. It would be evolutionarily disadvantageous for a person to go from skinny to Ahnold in a single workout, because their body would OVERcalibrate to the environment and be similiarly maladapted. Similarly, it would be disadvantageous if a person practiced approach behavior (i.e. extraversion) a single time and then became the life of the party — they would be maladapted to approach situations. It is good that our biological systems limit the progress of change. However, steroids have been developed to increase the rate at which muscle is rebuilt and to increase the amount of muscle that is rebuilt after a workout. A person can drastically improve their fitness if they are willing to deal with the side-effects. Are there trait steroids? Hallucinogenic drugs may be steroids for the trait openness. One study found a HUGE effect size for increase in openness following psychedelic mushroom use (Mcsomething, blah blah). Another unpublished study found that marijuana use codeveloped with openness (Robins, personal communication). And associative networks, implicated in creativity, seemed to expand when people took LSD and named objects on a flash card. Just like steroids, though, there may be side-effects of boosting openness — apophenia, or false-pattern perception, increases as openness increases. That could be why people on hallucinogens see visual hallucinations, but too much false-pattern perception may be detrimental to everyday life (consider the everything-is-connected paranoia of schizophrenics (or your stoned friend in college)).

What is clear is that this is not a perfect metaphor — biological systems promoting neural connection are not the same as biological systems promoting muscle growth. But this exercise (pun intended) may stimulate further thought that can help us develop theories of trait change.

The Replicability Crisis As It Applies To Big Datasets

The hallmark of science is that its results can be reproduced. If I shine light through a prism, and I describe what I see, you should be able to read what I wrote and do the experiment again, yourself, and get the same results. That’s why science isn’t opinion, and why it labels itself empirical. Unfortunately, reproducibility rates aren’t the 95% we hoped for; they’re nowhere close.

People like to talk about this. It’s a very important topic. And, a series of solutions have been developed that seek to improve replicability, or to at least mark the studies that are more likely to replicate (preregistration, registered replication reports, the 21-word solution). But, unfortunately for people like me that do personality development research with large, already-collected archival datasets, these discussions don’t apply very well. Often, near-term replication is impossible, because there aren’t any other datasets have collected the same variabiles as the ones you are examining (much of this is a function of personality development being a relatively new science; there aren’t too many long-running studies with Big Five variables collected at multiple time points). Researchers who have found that some personality traits codevelop with obesity over time (Sutin et al., 2009) don’t have another dataset to replicate this finding with.

The easy solution to this problem is to pre-register. If a person reports their intended procedure and their theories ahead of time, there is no wiggle room for them to flip thousands of coins and only report the string of four heads in a row. Unfortunately, this solution isn’t viable to most personality development researchers for two reasons. First, we don’t know what we’re working with until we peek at the data, and after we peek at the data, we can’t pre-register any longer, because we know what’s in the data to some extent. A friend of mine was interested in looking at schizoid tendencies and personality, until she looked at the data and discovered that too few participants actually reported schizoid tendencies, precluding any further statistical tests. Pre-registration, for her, would have been a huge waste of time. Second, we have so few datasets to work with that we often re-use datasets in future studies. As part of one study, I analyzed openness. In the process, I learned about how that scale functioned in the dataset — older people were less open, and everyone answered the questions similarly across the lifespan. So now, I can’t pre-register any study using that openness variable and that dataset, because I know to some extent how openness functioned, and that will influence my subsequent analytic decisions and bias them towards significance.

So, what do I do if I can’t replicate because there aren’t any longitudinal datasets for me to replicate with, and I can’t preregister because I’ve peeked at the data? I can tailor the strength of my conclusions to try to account for the inevitable P-hacking I’ve done. Thankfully, I already try to do that, and so do other personality researchers for the most part. Everything is explicitly labeled as exploratory, and all causal language is preceded by the words “may” or “potentially.” But, we all lie to ourselves when we say we don’t P-hack. We definitely tailor our analytical decisions to what we see in the data. I found that openness and time spent reading books weren’t nearly as related as I thought they would be, and I explained this by mentioning all the bestselling Shades of Gray that everyone is reading that aren’t doing anything for their openness. But, had I found something, I would probably have continued analyses. And that’s something that i CAN admit to myself; I probably made countless other decisions like this that biased my findings towards significance, and all  I can do is walk it back with my words.

Long story short, if there is a replication crisis in personality development, it’ll be a long time before we will even know. So let’s do the research as best as possible the first time: build analysis plans for our data after checking the initial descriptive statistics, stow em in our labs somewhere, and don’t deviate from them. Report all tests and all data exclusions. And, if other datasets show up with the variables you’ve analyzed, give em a shot, and cross your fingers!



Personality correlates of ASMR

Ever listened to an ASMR video? If you haven’t, you’re in for a treat:


Give that video a listen for a couple of minutes, or as long as you can stand it, really. Did you feel a tingle down your spine? ASMR “chill” reactions, as far as I’ve deduced from informal conversations and message board reading, seems to be a pretty consistent individual differences variable. That is, some people get chills down their spine as soon as Dr. Dimitri starts whispering. Some people (such as me) can watch the entire video and feel (relatively) regular.

Why care about ASMR chills as an individual difference variable, given that basically all differences in affect, cognition, and behavior (depression, intellect, friendliness) exist on a continuum within the human population (Wilt & Revelle, 2016), and correlate (by definition) in some way with Big Five personality (Goldberg, 1992)?

Well, the personality correlates of ASMR chill-sensitive people can inform our knowledge of biological systems of personality. For example, consider another type of chills — aesthetic chills. You know, when you listen to music and get shivers down your spine (that are nonetheless distinctly different from ASMR chills)? This is oversimplifying, but that’s a rush of dopamine. You know who gets aesthetic chills? People high in openness. By this, we can link openness to dopaminergic function in some way.  Natural extensions to schizophrenics follow: they have too much dopamine, and they also exhibit clinical symptoms of high openness, like perceiving false patterns (such as conspiracy theories and paranoia).

Are ASMR chills dopaminergic? Who gets ASMR chills? Answering these questions can get us preliminarily closer to a biological understanding of human personality. While it’s not as direct as going into a rat brain, I doubt that rats get chills from watching Dr. Dimitri. Sometimes we’re forced to study people by studying people.