Social immunity

Social insect colonies have evolved collective immune defences against parasites. These 'social immune systems' result from the cooperation of the individual group members to combat the increased risk of disease transmission that arises from sociality and group living. In this review we illustrate the pathways that parasites can take to infect a social insect colony and use these pathways as a framework to predict colony defence mechanisms and present the existing evidence. We find that the collective defences can be both prophylactic and activated on demand and consist of behavioural, physiological and organisational adaptations of the colony that prevent parasite entrance, establishment and spread. We discuss the regulation of collective immunity, which requires complex integration of information about both the parasites and the internal status of the insect colony. Our review concludes with an examination of the evolution of social immunity, which is based on the consequences of selection at both the individual and the colony level.     

Social Suffering

Social Suffering. Arthur Kleinman. Veena Das. and Margaret Lock. eds. Berkeley. University of California Press, 1997. 404 pp.     

Social neuroendocrinology

In this paper we provide a critical review of research concerned with social/environmental mechanisms that modulate human neuroendocrine function. We survey research in four behavioral systems that have been shaped through evolution: competition, partnering, sex, and pregnancy/parenting. Generally, behavioral neuroendocrine research examines how hormones affect behavior. Instead, we focus on approaches that emphasize the effects of behavioral states on hormones (i.e., the “reverse relationship”), and their functional significance. We focus on androgens and estrogens because of their relevance to sexually selected traits. We conclude that the body of research employing a reversed or bidirectional perspective has an incomplete foundation: participants are mainly heterosexual men, and the functionality of induced shifts in neuroendocrine factors is generally unknown. This area of research is in its infancy, and opportunities abound for developing and testing intriguing research questions.