This talk will describe initial results of a study designed to classify differences in the development of proficiency in hypothesis testing by introductory students based on dispositions exhibited by the students. The talk will define five components that comprise statistical proficiency as well as the general concept of a psychological disposition and two particular dispositions. Findings from the psychology literature on human reasoning as they relate to statistics learning will be discussed briefly. Results of a quantitative study linking cognitive dispositions to statistics learning will be presented and a qualitative study designed to further understand the relationship will be described.