To understand the role of culture in cognitive development, it is helpful to consider the processes involved in terms of three levels of social grouping: human beings as a mammalian species, societies (thought of as the population of a particular geographical and political region that exhibits common cultural features), and cultural practices (thought of as recurrent ways of accomplishing valued social activities in concert with some group of one’s proximally circumscribed social unit). ese levels are not independent of each other. It is helpful to think of each “smaller” unit of cultural analysis as embedded within the more inclusive levels both spatially (in terms of the number of people involved) and temporally (in terms of time span over which the given cultural feature or formation has existed). Just as geopolitically defi ned populations can be thought of as branches of a tree of human life extending back to Australopithecus, so the diff erent cultural practices within a society represent variations in the ways that people organize their everyday lives within the set of possibilities to be found in highly similar ecological circumstances. Consequently, specifying the linkages among specifi c cultural practices within more inclusive sociocultural formations and the linkages of those sociocultural formations within historically formed modes of life is a major ongoing challenge to the study of culture and cognitive development.