Abstract: Both humans and group-living animals associate and behave affiliatively more with some individuals than others. Human friendship has long been acknowledged, and recently scientists studying animal behaviour have started using the term friendship for close social associates in animals. Yet, while biologists describe friends as social tools to enhance fitness, social scientists describe human friendship as unconditional. We investigate whether these different descriptions reflect true differences in human friendship and animal close social associations or are a by-product of different research approaches: namely social scientists focussing on proximate and biologists on ultimate explanations. We first stress the importance of similar measures to determine close social associations, thereafter examine their ultimate benefits and proximate motivations, and discuss the latest findings on the central-neural regulation of social bonds. We conclude that both human friendship and animal close social associations are ultimately beneficial. On the proximate level, motivations for friendship in humans and for close social associations in animals are not necessarily based on benefits and are often unconditional. Moreover, humans share with many animals a similar physiological basis of sociality. Therefore, biologists and social scientist describe the same phenomenon, and the use of the term friendship for animals seems justified.

Abstract: Argues that conceptual analysis should be rejected in favour of a more naturalistic approach to epistemology. There is a robust natural phenomenon of knowledge; knowledge is a natural kind. An examination of the cognitive ethology literature reveals a category of knowledge that does both causal and explanatory work. It is argued that knowledge in this very sense is what philosophers have been talking about all along. Rival accounts of knowledge that are more demanding—requiring either that certain social conditions be met or that an agent engage in some sort of reflection—are discussed in detail, and it is argued that they are inadequate to the phenomenon. In addition, it is argued that the account of knowledge that emerges from the cognitive ethology literature can provide an explanation of the normative force of epistemic claims.