2022 Update: My own results mentioned below replicated in a paper now published in Review of Philosophy and Psychology. Free paper, audiopaper, and link to the journal’s version here.
Philosophy helps us reason better, right? I mean, taking courses in analytic philosophy and argument mapping does more for students’ critical thinking than even critical thinking courses do (Alvarez-Ortiz 2007). And the more training one has in philosophy, the better one does on certain reasoning tasks (Livengood et al 2010). So it’s no accident that philosophy majors tend to outperform almost every other major on the GRE, the GMAT, and the LSAT (“Why Study Philosophy…“; see also Educational Testing Service 2014). That’s why people like Deanna Kuhn have such high praise for philosophers’ reasoning (Kuhn 1991, 258-262).†
Reasoning expertise: We turn now to the philosophers…. The performance of the philosophers is not included in table form because it is so easily summarized. No variation occurs…philosophers [show] perfect performance in generation of genuine evidence, alternative theories, counterarguments, and rebuttals…. The philosophers display a sophisticated understanding of argumentative structure…. None of the philosophers [had] any special expertise in any of the content domains that the questions address…. The performance of philosophers shows that it is possible to attain expertise in the reasoning process itself, independent of any particular content to which the reasoning is applied.
But there’s much more to say about this. For instance, we might ask two questions about this evidence.
Two Questions
It’s one thing to claim that philosophers are better reasoners, but that’s not the same as being perfect reasoners. After all, philosophers might reason better than others and yet still be vulnerable to systematic reasoning errors. So we need to ask: Are philosophers’ prone to cognitive errors like everyone else?
Also, if philosophers are prone to cognitive error, what is the relationship between their errors and their philosophical views?
1. Are Philosophers Prone To Cognitive Error?
In order to understand the rest of the post, you will need to answer the question below. It should only take a moment.
A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?
The question comes from the Cognitive Reflection Test (CRT) (Frederick 2005). It is designed to elicit a quick answer. What answer first came to your mind?
If you are like most people, one answer quickly came to mind: “10 cents.” And if you are like many people, you had an intuitive sense that this answer was correct. Alas, 10 cents is not correct. You can work out the correct answer on your own if you like. The point I want to make is this: the intuitively correct answer to this question is demonstrably false. This suggests that answering this question intuitively constitutes an error in reasoning.
It turns out that philosophers are less likely than others to make this error.
Jonathan Livengood and colleagues found that the more philosophical training one had, the less likely one was to make this error (Livengood et al 2010). I replicated this finding a few years later (Byrd 2014). Specifically, I found that people who had — or were candidates for — a Ph.D. in philosophy were significantly less likely than others to make this reasoning error — F(1, 558) = 15.41, p < 0.001, d = 0.32 (ibid.).
Some philosophers performed perfectly on the CRT — even after controlling for whether philosophers were familiar with the CRT. However, many philosophers did not perform perfectly. Many philosophers made the error of responding unreflectively on one or two of the CRT questions. This implies an answer to our first question.
Answer: Yes. Philosophers’ reasoning is susceptible to systematic error.
So what about our second question?
2. Do Philosopher’s Errors Predict Their Views?
Among lay reasoners, the tendency to make this reasoning error on the CRT has correlated with believing that God exists, that immortal souls exist, that life experiences can count as evidence that a god exists, etc. (Shenhav Rand and Greene 2012). This finding is in line with a common theme in the research on reasoning: unreflective reasoning correlates with a bunch of religious, supernatural, and paranormal beliefs (Aarnio and Lindeman 2005; Bouvet and Bonnefon 2015; Giannotti et al 2001, Pennycook et al 2012, Pennycook et al 2013, Pennycook et al 2014a, 2014b).
And this finding has now been replicated among philosophers. Specifically, the more that philosophers were lured into the intuitively appealing yet incorrect answers on the CRT (e.g., “10 cents”), the more that they leaned toward or accepted theism — F(1, 559) = 7.3, p < 0.01, d = 0.16, b = 0.12 (Byrd 2014).
There is also evidence that people who make this error on the CRT are more prone to certain moral judgments. To see what I mean, read the scenario below (Foot 1967).
You see a trolley racing down its track towards five people. You happen to be standing near the switch that would divert the trolley down a sidetrack toward one person. If you pull the switch the trolley will surely kill 1 person. If you do not pull the switch the trolley will surely kill five persons. Do you pull the switch?
So? Would you pull the switch or not? Those who answered unreflectively on the CRT have been less likely to pull the switch (Paxton, Ungar, and Greene 2012).
Once again, it turns out that this finding holds among philosophers as well. Philosophers who were more likely to make a reasoning error on the CRT were less likely to pull the switch — F(1, 559) = 6.93, p < 0.001, d = 0.15, b = 0.17 (Byrd 2014).
Philosophers’ proclivity to make this error was also positively associated with other philosophical views:
- Physical (as opposed to psychological) views of personal identity — F(1, 558) = 8.57, p < 0.001, d = 0.17.
- Fregeanism (as opposed to Russelianism) about language — F(1, 558) = 8.59, p < 0.01, d = 0.17.
I have lots of thoughts about these findings, but I want to keep things brief. For now, consider the implied answer to our second question.
Answer: Yes. Philosophers’ reasoning errors are related to their views.
CONCLUSION
So there you have it. It would seem that philosophers are susceptible to systematic reasoning errors. And insofar as philosophers are so susceptible, they tend toward certain views. I’m tempted to say more, but I’ve already done so elsewhere (Byrd 2014) and I am working on a pre-registered replication of these findings for—among other things—my dissertation.††
† Thanks to Greg Ray for pointing me to this passage.
†† What does the rest of the literature suggest about philosophers’ reasoning? Unsurprisingly, the verdict is disputed (Nado 2014, Machery 2015, Mizrahi 2015, Rini 2015). Indeed, philosophers seem susceptible to the same tricks as anyone else (Schwitzgebel and Cushman 2015; Pinillos et al 2011). And second, even if philosophers are better reasoners, it’s not even clear why they are better (Clarke 2013). Why would philosophers be better reasoners than others? I sketch an account in Byrd 2014, Section 3 (see also Weinberg, Gonnerman, Buckner, and Alexander 2010).
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