Insensitivity to sample size
Insensitivity to sample size is a cognitive bias where people estimate the probability of obtaining a sample statistic without considering the sample size. For example, in one study, subjects assigned the same probability to the likelihood of obtaining a mean height of above six feet [183 cm] in samples of 10, 100, and 1,000 men.
Source: Wikipedia — Insensitivity to sample size (CC BY-SA 4.0)