Studies of the teaching practices used in adult reading programs suggest that these practices often reflect the personal perspectives of teachers on factors that contribute to less-skilled reading development. In this study, 19 adult reading teachers were interviewed to explore their perspectives on how adults become less-skilled readers and the origins of these perspectives. Four themes were identified in terms of teachers' perspectives, which attributed less-skilled reading respectively to: (a) learners' distinct needs not being met, (b) readers' "life baggage", (c) under-developed sense of joy in reading, and (d) inappropriate learning environments. Four main types of experiences appeared to have contributed to the development of these perspectives: (a) teachers' own experiences in learning reading, (b) teachers' general teaching experience, (c) teachers' experiences of teaching reading specifically, and (d) teachers' knowledge of formal reading theories and/or empirical research findings. Potential implications for enhancing the outcomes of adult reading instruction programs are discussed.