Inspection time (IT) and Peabody Picture Vocabulary Test (PPVT) scores from 75 school children aged 6-13 years in 2001 were compared with the performances of 70 children aged 6-13 years who had attended the same primary school in 1981 ["J. Exp. Child Psychol." 40 (1985) 1.]. ITs for the 2001 sample were measured with the same four-field tachistoscope and identical computer-based procedures followed by Wilson in 1981. The 2001 sample completed two versions of PPVT concurrently: PPVT (1965, Form A) as used in 1981 and PPVT-III (1997, Form IIIA). Mean ITs from both samples, 20 years apart, were essentially the same (123 +/- 87 and 116 +/- 71 ms in 1981 and 2001, respectively). There was, therefore, no evidence that speed of processing had improved. Correlations between IT and raw PPVT scores were significant (P is less than 0.01) for both 1981 (r = -0.43) and 2001 (r = -0.31). Within the 2001 sample, concurrent PPVT scores correlated 0.68; however, means revealed a significant Flynn effect. Thus, scores for the 2001 cohort on the earlier PPVT were higher (M standardized IQ 118.52 +/- 16.62) than the recently restandardized PPVT-III (113.97 +/- 12.23), although, compared in terms of the most recent standardization sample, the 2001 cohort was equivalent to the 1981 sample (113.66 +/- 16.72). The Flynn effect has nothing to do with speed of processing as measured by IT, despite the effect being strongest for ability tests that earn bonus scores for quick performance. Because IT correlates with IQ but appears to be stable across 20 years, whereas IQ is not, IT may have promise as a useful biological marker for an important component of cognitive decline during old age.