I first got interested in personality psychology long ago as a double-degree student of psychology and philosophy. I was intrigued by the psychology of philosophical divisions and started thinking about how people’s views of the world reflect their personalities. It seemed to me that there was frequently a coherence between the personalities of philosophers and the philosophical positions they adopted.
There are many historical examples consistent with this position. An example that comes to mind is Arthur Schopenhauer—a 19th century thinker known as the philosopher of pessimism, who was also known to be cynical and disagreeable in his personal life. Another obvious example is Immanuel Kant—an 18th century philosopher whose notorious rigidity, orderliness, and normative orientation dovetail with his rule-based philosophical system.
At the same time, one might object that it is easy to fall into confirmation bias and cherry-pick examples that fit with your thesis from the vast history of philosophy. A particularly vivid counterexample to the aforementioned thesis is that Karl Popper, who vigorously espoused critical rationality and impartiality in science, appears to have been dogmatic, self-aggrandizing, and intolerant of criticism of his own position. Furthermore, philosophy has become a great deal more specialized over the last century. Even if the grand philosophical systems of earlier generations would reflect the personalities of their architects, this would not mean that contemporary philosophers are necessarily influenced by their personalities in their work.
Whether there is a congruence between personality and philosophy or not is an empirical question. There are a few, mostly small, studies on the congruence between the theoretical stances and personalities of scientists. For instance, a study by Johnson et al. (1988) suggsted that individuals with a mechanistic worldview were more inclined toward behaviorism and less toward developmental perspectives and more “orderly, stable, conventional, and conforming, objective and realistic in their cognitive style, and interpersonally passive, dependent, and reactive”. Research on personality and philosophical predilections has, however, been even more scarce.
One of my goals as a doctoral student was to investigate the association between personal worldview and philosophical beliefs and intuitions. Twelve years ago, I managed to collect some data. Undergraduate students at New York University responded to a wide range of questions designed to assess their personal worldviews (e.g., concerning human nature, society, knowledge, moral issues, and emotions), their endorsement of philosophical doctrines, and their intuitions in paradigmatic philosophical thought experiments. I never published the results, because the study yielded mostly null results, the sample was quite small, and I thought that it is possible that young students (most of them were not more than twenty years old) do not yet (if ever) know where they stand on philosophical issues. Surveying actual philosophers would of course be ideal, by I did not pursue this possibility further as I did not have the practical resources needed to do so.
I was recently delighted to see that two other researchers have finally published a study of this nature—this is what prompted me to revisit this topic and write this blog post. In a sample of 314 philosophers, Yaden and Anderson (2021) found that “higher interest in numeracy predicted physicalism, naturalism, and consequentialism; lower levels of well-being and higher levels of mental illness predicted hard determinism; using substances such as psychedelics and marijuana predicted non-realist and subjectivist views of morality and aesthetics; having had a transformative or self-transcendent experience predicted theism and idealism.” One might add here that some other researchers have suggested that consequentialism may be associated with cognitive processing (as opposed to emotional processing) and with antisocial personality traits, which fits with the ubiquitous stereotype of the cold and calculating utilitarian.
Yaden and Anderson (2021) found little support for an association between traditional personality trait dispositions and philosophical views (consistent with my own results). It should, however, be noted that they only measured the “Big Five” personality traits (i.e., extraversion, neuroticism, conscientiousness, agreeableness, and openness). They did not measure worldview components of personality such as values or beliefs, which are more likely to be linked to philosophical positions and intuitions. They did not validate the measure of philosophical positions either. The conclusions particularly with respect to personality must therefore be considered preliminary. The results are interesting, nonetheless.