The internal consistency reliability and discriminant validity of the adult version of the Matching Familiar Figures Test (MFF) were determined for a sample spanning adulthood; age and sex differences were also investigated. Sixty-three men and 63 women ranging from 18 to 78 years of age, with at least 12 years of schooling, were administered Kagan's MFF and the vocabulary subtest of the Wechsler Adult Intelligence Scale (WAIS). While internal consistency reliability was high for the latency scores, it was only moderate for the error scores. As expected, error and latency scores were strongly related and were orthogonal to verbal ability. Results of a multivariate analysis of variance and follow up analyses indicated that older adults had significantly longer latencies than middle-aged and younger adults. Reflectivity in older adults was suggested to be part of a general pattern of slowing down in both cognitive and pscyhomotor activities. Therefore, further research aimed at modifying the cognitive tempo of young, middle-aged, and older adults was advocated. However, such research must be preceded by revision of the adult version of the MFF so that it is more reliable. (Author/RD)