Individual Differences and Conflicting Intuitions in Explaining Variance in Philosophical Thought Experiments

When people are asked about philosophical thought experiments, the result is usually that different people give different responses. A question arises as to whether this variance is primarily a matter of differences between different people (between-person variance) or primarily a matter of each individual person giving different answers on different occasions (within-person variance). We disentangle these two sources of variance by administering five different thought experiments to participants and then giving them the same thought experiments again two weeks later. Across the five thought experiments, 66% to 79% of people gave the same answer both times. Using the intraclass correlation, we can compute the proportion of person-variance vs. within-person variance. Across the thought experiments, 25% to 52% of the total variance was between-person variance. Overall, these results indicate that a substantial proportion of the variance in responses to philosophical experiments is due to stable individual differences. Further research can explore which specific individual differences account for the between-subject variance and which specific cognitive processes account for the within-subject variance, but although the present study does not address those questions, it does provide an estimate of the total proportion of variance due to each of these sources.