Abstract
Two studies, involving a total of nearly 500 Ss, were conducted to determine the mechanisms by which processing speed contributes to the relations between adult age and associative learning. Results of both studies indicated that increased age was related to poorer associative learning largely because of a failure to retain information about previously correct responses. This in turn was related to the effectiveness of encoding briefly presented information in an associative memory task, which was related to measures of processing speed. It is therefore suggested that age-related decreases in speed of processing lead to less effective encoding or elaboration, which results in a fragile representation that is easily disrupted by subsequent processing.