Groups of younger and older adults were administered numerical and arithmetical tasks that varied in the extent to which they assess evolved versus culturally specific forms of cognition, termed biologically primary and biologically secondary abilities, respectively. Componential analyses of solution times suggested that younger adults are faster than older adults in the execution of biologically primary processes. For biologically secondary competencies, a pattern of no age-related differences or an advantage for older adults in speed of processing was found. The results are consistent with the view that there has been a cross-generational decline in arithmetical competencies in the United States and are discussed in terms of models of age-related change in cognitive performance.