Experimental work regularly finds that individual choices are not deterministically rationalized by well-defined preferences. Nonetheless, recent work shows that data collected from many individuals can be stochastically rationalized by a distribution of well-defined preferences. We study the relationship between deterministic and stochastic rationalizability. We show that a population can be stochastically rationalized even when half of the individuals in the population cannot be deterministically rationalized. We also find the ability to detect individuals who are not deterministically rationalized from population level data can decrease as the number of observations increases.