This paper argues for an interdisciplinary approach to beliefs about language learning research, and suggests that current studies in this area do not go far enough to examine the extent to which stable factors, such as individual learner differences, account for the nature of beliefs. Next, it elucidates how cognitive and personality psychology provides a foundation for a possible relationship between learner beliefs and personality, and emphasizes the need for further research and a strong theoretical foundation before any attempts to change language learners' beliefs are made in the classroom context.