 Among Kahneman and Tversky’s earliest findings was that people tend to make statistical inferences from samples that are too small, even when given the opportunity to control the sampling procedure. Kahneman and Tversky attributed this effect to a systematic failure of people to appreciate the biases that attend small samples, although Hertwig and others have offered evidence that samples drawn from a single population are close to the known limits to working memory (Hertwig, Barron et al. 2004).