Recent research on adult intellectual development indicates that there is little justification for the notion of marked intellectual decrement in the aged. Rather, the aged person appears to exhibit a pronounced degree of plasticity in intellectual performance, suggesting that it is necessary to explore environmental variables related to cognitive proficiency. An operant framework is proposed for the analysis of environment-intelligence interactions in old age, and intellectual decrement is interpreted to reflect the lack of supportive environmental contingencies. In conclusion, it is argued that such a framework demands the implementation of research aimed at examining the range of modifiability of intellectual performance in the elderly.