Human Evolution and the Capacity to Categorize Laureano Castro and Miguel A. Tar0 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK We zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA have studied-with the belp of a ma&ma&l model of cultural tramm&io~ ~ -cvolutionary &cc@ which may derive from the appearance of a fzonccptual capa@ to catcgoriz behavior (approving or disapproving of it) in one of our hominid ancestors. We consider acqui&ion of behavior througb individual kam@ and rudimentarycultursltnmrmission.Theabilitytocatego~ behaviorproducuan increwillthedfi&rqand the fkxibility of the cultural trlmsmGoll process. Moreover, the capacity to CateeoriEe allows the acqq through cukural tra~ missio~ of information about behavior, similar to that provided by individual learning (i.e., an individual!4 ir~ tcractio~ ~ witb the environment. in con- to the receipt of luuon6 learned by othem) but avoid8 unwemwy costs by not having to resort to exp&nce. An ana@& of the model rev& that the advantage in terms of fitness in individuals capabk of categorizing compared to individuals without this ability the probabilcy that behavior with adaptive can be developed without the need of culture, Lt is, solely through individual leaming F&y, we suggest that intcll@cc has developed, within this framework oftbecul~ ~ on,asantwsystem,outsidethc~ ~ ~ ~ system,~ ableofllencrating Vale and showing prdw between di%xent kinds of behavior. Phenotypic flexibility understood as an open programming of behavior has developed phylogenetically in the form of individual learning together with an increase in the complexity of the nervous system. Although the distinction between innate and acquired behavior is not neat, we can say that individual learning, from conditioned reflexes to intelligent innovation, has turned out to be a valid alternative to genetic transmission of patterns of rigid behavior. In speck having a certain individual learning capacity, the development of a system of cultural transmission can turn out to be adaptive, since it allows a reduction in the time and cost involved in such learning (Boyd & Richerson, 1985; Pulliam & Dunford, 1980), and takes advantage of the range of behavior developed by the previous generation