Different hypotheses identifying factors affecting the complexity of implements used to obtain food resources by hunter-gatherer groups are assessed with regression analysis. A regression model based on interaction between growing season as a proxy measure for risk and number of yearly moves fits data on the complexity of implements for 20 hunter-gatherer groups. The interaction model leads to a division of hunter-gatherer groups into two subgroups that correspond to collector vs. forager strategies for procuring resources. Implications of the interaction model for the evolution of complex implements are discussed.

An Algebraic Account of the American Kinship Terminology by Dwight W. Read ALTHOUGH THE STUDY OF KINSHIP SYSTEMS has been a major focus for anthropological research since at least the time of Morgan, a completely satisfactory means for defining, characterizing, and analyzing the internal logic that structures a kinship terminology has remained elusive. Morgan's (1871) preliminary distinction of descriptive versus classificatory systems, Kroeber's (1909) seminal paper developing the concept of alternative dimensions along which culturally determined distinctions are said to be realized, and Rivers's (1900) "genealogical method" all still form basic approaches to the study of kinship terminology structure, even though none of these or their subsequent schools of thought has led to a completely sufficient analysis of structure as a form generatable by the logic of a few basic principles (cf. Radcliffe-Brown 1941; Lkvi-Strauss 196934, 493). Componential analysis, the logical consequent to Kroeber's work, has only partially succeeded in laying bare elementary rules, operations, and equations from which a terminology structure may be deduced. While it has provided a method both for presenting and comparing different kinship terminologies in a common idiom and for delineating aspects of the structure of kinship terminologies, exemplars of the componential-analysis method based on the American kinship ter

In this paper I explore the possibility that recursion is not part of the cognitive repertoire of non-human primates such as chimpanzees due to limited working memory capacity. Multiple lines of data, from nut cracking to the velocity and duration of cognitive development, imply that chimpanzees have a short-term memory size that limits working memory to dealing with two, or at most three, concepts at a time. If so, as a species they lack the cognitive capacity for recursive thinking to be integrated into systems of social organization and communication. If this limited working memory capacity is projected back to a common ancestor for Pan and Homo, it follows that early hominid ancestors would have had limited working memory capacity. Hence we should find evidence for expansion of working memory capacity during hominid evolution reflected in changes in the products of conceptually framed activities such as stone tool production. Data on the artifacts made by our hominid ancestors support this expansion hypothesis for hominid working memory, thereby leading to qualitative differences between Pan and Homo. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯The substantial differences in cognitive abilities between Homo sapiens and non-human primates (see Parker and McKinney, 1999 for a recent review) simply reflect, according to some researchers (e.g., Finlay, Darlington, and Nicastro 2001; Marino, 2006, among others), quantitative extension of cognitive capacities already present in a common ancestor for Pan and Homo via allometrically scaled expansion of brain structures. Support for this viewpoint is seen in the fact that behavioral traits supposedly making Homo sapiens cognitively unique among the primates are also present in non-human primates. Even culture -often been viewed as providing the firmest evidence for a qualitative divide (Derksen, 2005;Holloway, 1969;Wimsatt and Griesemer, 2007) -may have precursors, it is argued, in non-human primates in the form of group specific behavior transmitted non-genetically through imitation or learning within a social context (de Waal and Tyack, 2003; Lycett, Collard, and McGrew, 2007, among others). Defining culture through behavior and its mode of transmission, though, ignores the distinction made by cultural anthropologists between custom or tradition and culture, with

The standard model of population growth and regulation is critiqued. It is argued that any model of population growth and regulation must accommodate ten propositions, and a multitrajectory model that does so is described. This model identifies competition between groups, individual choice in reproductive behavior, the scale for spatial and temporal variation in resource abundance, and the social unit for resource access and ownership as important components of population behavior.

A recent article has suggested that maintenance of complex tools and associated tasks in a group depends on the presence of skilled individuals to serve as targets for imitation. The expected number of skilled target individuals, it is argued, relates to the population size. It is predicted that population size and maximum complexity of tools and/or tasks should correlate, hence a decrease in population size could lead to maladaptive loss of skills. Data from Tasmania are said to support the argument. However, the argument neither agrees with the archaeological data from Tasmania nor ethnographic observations on hunter-gatherer societies. Instead of being an example of a group that underwent maladaptive loss, the indigenous people of Tasmania appear to have used tools sufficient for the tasks at hand. An alternative model is proposed that distinguishes between motor skills and knowledge needed to do tasks effectively and takes into account assessment of the time cost for developing skills. Loss of skills more likely relates to change in the mode of resource procurement or change in technology rather than a shortage of skilled, target individuals due to decrease in population size.