We recently talked to Niclas Kuper about his paper, "Resting frontal EEG asymmetry and personality traits: A meta-analysis", which will appear in an upcoming issue of EJP. Niclas is a master’s student at the University of Hamburg, Germany.
Read more about the study below!
Q: Hello Niclas! Can you tell us a little about yourself and what got you interested in personality psychology?
I’m a psychology student from Hamburg in Germany and I’m currently finishing my master’s degree there. I’ve always been interested in why people differ from each other and expected this question to be answered in my psychology studies. During my first two undergraduate semesters, I was surprised by how much of the variation in dependent variables was left unexplained in psychological research. The variation within experimental conditions is often much larger than the variation between them. In my third semester, I found out that at least part of this variation is actually systematic variance attributable to individual differences. This was discussed in the Differential Psychology lecture held by Jan Wacker, which I really enjoyed. I got the impression that the field of personality psychology aligned really well with my interests in both personality and rigorous quantitative methods. Furthermore, personality psychology provided a big picture view of human behaviour by integrating concepts from various subfields of psychology. Given my enthusiasm for the research area, I started working in the lab of Jan Wacker and was lucky enough to be part of many interesting projects.
Q: What aspects of research are you most excited about?
I think it’s very exciting that we can ask important questions about human nature and then try to answer them empirically.
As far as current developments in psychology in general go, I’m particularly excited about trends towards an emphasis on replicability and open science. I consider myself very lucky to have started studying psychology when this movement was already underway. More recently, more attention has also been drawn to the issue of measurement. Simply put, several measures - for instance behavioural task measures or physiological indicators - might not map onto the psychological constructs that we think they do. This conclusion also applies to the physiological indicator investigated in my current study.
In the field of personality psychology, I’ve become particularly interested in moving from descriptive towards explanatory accounts of personality. This can be approached by studying the biological or social-cognitive processes underlying personality manifestations. Currently, I’m fascinated by personality x situation interactions, that is, whether the impact of personality on our states (physiology, behaviour, cognition, affect) depends on the situation we’re in. Traits can be conceptualized as dispositions to show certain states in trait-relevant situations. This idea has also influenced the discussion section of my current study.
Q: Can you tell us about your study?
The study that I did with Wiebke Käckenmester and Jan Wacker is a meta-analysis on the relationship between resting frontal asymmetry and personality traits. Frontal asymmetry describes the relative activity of the left vs. right frontal cortex and is assessed via EEG. It has been widely used as an indicator of emotion, motivation and psychopathology. Relative left-frontal activity is typically interpreted as an indicator of approach motivation, whereas right-frontal activity is thought to be associated with withdrawal motivation or behavioural inhibition. When it comes to individual differences, frontal asymmetry is typically assessed during rest: The participant sits calmly with closed eyes or while looking at a fixation cross. Frontal asymmetry during this weak and ambiguous situation has been related to various personality traits, most prominently to individual differences in the behavioural approach system (BAS) and the behavioural inhibition system (BIS).
Given some replication failures for the relationship between resting frontal asymmetry and personality traits, we sought to investigate whether such a relationship exists and what its magnitude is. We identified five clusters of traits that have been associated with resting frontal asymmetry: (1) Extraversion, including BAS and trait positive affect (2) Neuroticism, including BIS and trait negative affect, (3) Impulsivity, (4) Anger, and (5) Defensiveness. Overall, 79 studies with 5700 participants were included in our meta-analysis.
We found that the relationship between resting frontal asymmetry and self-reported personality traits is much smaller and less replicable than expected. Specifically, the relationships with Extraversion, Neuroticism, Impulsivity, and Anger were very small - much smaller than an effect that could be realistically studied in a single laboratory and potentially zero, when taking into account publication bias. In sum, our findings indicate that after decades of research, there is still no convincing evidence that resting frontal asymmetry is systematically associated with self-report measures of personality.
I think that our findings make a good case for a shift in research towards examining frontal asymmetry as a state variable rather than during rest. Several studies have examined state frontal asymmetry as an indicator of motivation and emotion and there is some preliminary evidence that personality traits might be more strongly related to state frontal asymmetry in situations relevant to the trait in question. This resonates well with the previously mentioned idea of traits as dispositions for certain states. For instance, trait approach motivation might only be associated with frontal asymmetry in reward contexts, because it predisposes individuals to experience approach motivation when rewards are present.
However, even when examining frontal asymmetry as a state variable, many important challenges remain. Future research should systematically investigate the effects of different methodological parameters such as reference scheme or electrode pair. Furthermore, our findings highlight that very small or even non-existent effects survived in the literature for decades. This implies that subsequent research should embrace open-science practices to prevent this issue from recurring: Future studies should be pre-registered and adequately powered for the study of small to medium-sized effects. This could be achieved by large collaborative projects.
Q: Where do you see yourself in the (near) future?
I’m currently in the process of finishing my master’s degree and would like to start my PhD towards the end of this year. I’m excited to further pursue my interests in personality psychology and would like to contribute to our understanding of the processes underlying personality manifestations. Currently, I’m interested in personality x situation interactions and ways to measure the psychological situation. I believe that these questions are particularly relevant for several theories of personality as well as subsequent research on personality dynamics. If all goes well, I would like to stay in academia beyond my PhD.
Q: Do you have any tips or advice for young researchers?
I’m a very early career researcher myself, so my advice is necessarily very limited. However, a few things have worked well for me. One thing that is becoming more and more valuable in academic psychology is the statistics program R. It’s extremely useful for data aggregation, data analysis, and simulations. Learning and heavily using R has helped me tremendously on my current path.
Furthermore, I think young scholars should embrace open science practices such as pre-registration whenever possible. Beyond being important for the field itself, it’s also very useful for the individual researcher because it forces you to articulate your specific hypotheses theoretically and statistically before analysing the data. This vastly improves the clarity of your ideas early on in the research process.
Finally, it’s of course important to pursue your passions and work on projects that you’re truly excited about.
Q: What do you like to do in your spare time?
I really enjoy being outdoors, particularly in forests and near the ocean or other waters. I also like cooking and baking with friends (shout-out to my cooking group). I have recently gotten into breadmaking, which is a lot of fun! As far as more cultural activities are concerned, I enjoy playing the guitar, going to concerts, and going to the theatre. Somewhat of a guilty pleasure of mine is watching Netflix shows of questionable quality.