This article uses the recent controversy about Little Albert's identity as an example of a fine case study of problems that can befall psychologist-historians and historians who are unaware of their tacit assumptions. Because bias and logical errors are engrained in human habits of mind, we can all succumb to them under certain conditions unless we are vigilant in guarding against them. The search for Little Albert suggests 2 persistent issues: (a) confirmation bias and (b) that overconfidence in a belief detracts from reasoning because logical errors are intuitive and seem reasonable. This article uses cognitive psychology as a framework for understanding why these issues might have arisen in the Albert research and passed the scrutiny of peer review. In closing, the article turns to historians' writings to gain insight into rules of thumb and heuristics that psychologist-historians and historians can use to mitigate these concerns. (PsycInfo Database Record (c) 2020 APA, all rights reserved).