 Finally, we would like to highlight connections between Simpson’s Paradox and other reasoning fallacies in the literature. First, the base rate fallacy is related to Simpson’s Paradox since the illusion that association reversal is impossible may be based on a neglect of the different base rates for treated and untreated people, given the third variable (Bar-Hillel 1990). Second, the fallacy of mistaking correlation for causation may contribute to the appearance of paradoxicality since association reversal implies two contradicting causal claims, when combined with this fallacy. Third, in both Simpson’s Paradox and the Monty Hall fallacy reasoners fail to see the probabilistic relevance of causal information. While in Simpson’s Paradox, reasoners ignore the relevance of a back-door path for an observed association, in the Monty Hall problem, reasoners fail to take into account how Monty’s action depends on his knowledge of what is in back of the doors. Fourth, and last, the capacity of reasoners to detect the causes of association reversal also depends on the extent of the confirmation bias to which they are exposed (e.g., whether or not they find a discrimination mechanism plausible). We are unaware of systematic research into the connection between Simpson’s Paradox and these reasoning fallacies, but this could be a fruitful field for future research. There is perhaps nothing paradoxical about Simpson’s Paradox, but since we often struggle to understand it, our reasoning about association reversals may be entangled with various forms of reasoning that are susceptible to bias and error.