In this article, we attempt to provide an overview of the features of the abilities, aptitudes, and frames of minds that are attributed to critical thinking and provide the broad outlines of the development of critical-analytic thinking (CAT) abilities. In addition, we evaluate the potential viability of three main hypotheses regarding the reasons for developmental trends in CAT and address problems of achieving the ideal of a critical-analytic thinker at all age levels. The first hypothesis is that standard instruction in disciplines such as the sciences and social sciences, couch findings, and theories as matters of choice rather than as inferences is being more warranted than others. The second hypothesis is that there are developmental constraints on the expression of CAT that would limit the efficacy of instruction seeking to promote increased appreciation for inferential warrants and the idea of progress in disciplines. These constraints could be tied to the acquisition of knowledge, development of expertise, and brain development. The third hypothesis pertains to motivational reasons for not exerting the time and effort required to engage in CAT. We conclude by proposing a research agenda to investigate these hypotheses, as the first step in understanding the kinds of interventions that might be needed to increase the level of CAT expressed in high school and college graduates.