Our social roots

Abstract

We share many behavioural traits with our primate relatives — some disquietingly nasty. BOOK REVIEWED-Gorilla Society: Conflict, Compromise and Cooperation Between the Sexes by Alexander H. Harcourt & Kelly J. Stewart University of Chicago Press: 2007. 416 pp. $75 (hbk), $30, £19 (pbk) BOOK REVIEWED-Macachiavellian Intelligence: How Rhesus Macaques and Humans Have Conquered the World by Dario Maestripieri University of Chicago Press: 2007. 192 pp. $25, £14 BOOK REVIEWED-Chimpanzee Politics: Power and Sex Among Apes by Frans de Waal 25th Anniversary Edition. Johns Hopkins University Press: 2007. 276 pp. $24.95, £16.50 Why do you spend more time with your colleague next door than the one down the hall? As a founding scholar of primate social behaviour, the fifteenth-century philosopher Niccolò Machiavelli might have been able to tell you. Today's primatologists are still fascinated by the evolutionary roots of power, sex and politics in human and non-human primates — surprising parallels emerge that may explain facets of our behaviour and codes governing our society. A seminal book in the field is Frans de Waal's Chimpanzee Politics, just re-released as a 25th-anniversary edition. De Waal explores interactions among three high-ranking males in the Arnhem Zoo colony in the Netherlands to obtain insight into alliances, sex and power in our closest living relatives. The chimpanzees' lives include all the intrigue and shifting allegiances of the Florentine court; it is easy to forget that the participants are not human. Our social roots G. ELLIS/MINDEN PICTURES/FLPA Family feast: endangered mountain gorillas (Gorilla gorilla beringei) enjoying a vegetarian menu together. A quarter of a century after its first publication, the influence of de Waal's approach is pervasive. Dario Maestripieri's engaging new book, Macachiavellian Intelligence, argues that social cognition is the key to our species' extraordinary success. The book is also a salutary reminder that we are members of the Order Primates as much as of the Family Hominidae, and not all that different from our disquietingly nasty cousins. Rhesus macaques and humans, Maestripieri explains, are group-living generalists who succeed by advancing their own — and their family's — future through political manoeuvring. Altruism and social behaviour are therefore useful only when the pay-off is greater than the investment, although, according to Maestripieri, humans may have recently evolved more pervasive pro-social tendencies. Some may question Maestripieri's pragmatic approach to human behaviour, such as his view that our sexual patterns were shaped to secure partner commitment. But, his use of anecdote, and comparisons between humans and macaques, make a persuasive case that a self-interested desire to manipulate others motivates much of human behaviour. An understanding of how society determines the behaviour of individuals calls for an examination of an outgroup that varies in its degree of relatedness or its social organization. Gorillas, with their harem societies and lesser aggression, provide a nice counterpoint to chimpanzees and macaques (excepting, perhaps, the little studied but apparently more gregarious western gorilla). Gorilla Society aims to develop a socio-ecological framework for understanding the animals' social organization and behaviour. Harcourt and Stewart's book contains some novel approaches. For example, the authors attempt to model rarely seen behavioural variants in order to estimate their pay-offs, which helps in understanding previously unexplained behaviour. They also approach social organization from the male and female perspectives, developing a picture of infinite regress as the decisions of each sex affect each other's choices. They explain, among other things, the conspicuous absence of male takeovers in gorilla populations. Every chapter ends with a comparison between gorilla behaviour and that of chimpanzees, bonobos and orangutans in similar circumstances, illustrating the broader power of socioecological theory. The authors of all three books are noted primatologists. Although aimed at different audiences, the books are all readable and informative. There is some repetition in Harcourt and Stewart's because it is written as a reference work; extensive cross-referencing and helpful section headings make it easy to use. Maestripieri's slimmer volume will appeal to a general audience with its fast pace, references to popular culture and wide-ranging discussion of human behaviour. It cites the original studies, but could leave primatologists wishing for more in-depth discussion. Just as we are on the brink of a more nuanced and thorough understanding of primate and human society, the breakdown of human society continues to fuel the demise of the remaining strongholds of primates in the wild. For instance, gorillas are now listed as critically endangered by the World Conservation Union (Nature 449, 127; 2007). Contrary to his stereotype, Machiavelli believed that force should be mitigated with prudence, that morality must not be abandoned. Where is our prudence and morality when we ignore the fate of other peoples and species who share our planet? Humans should find a way to narrow the gap between our own well-being and that of our fellow creatures. Top of page 1. Sarah F. Brosnan is an assistant professor in the Department of Psychology, Georgia State University, PO Box 5010, Atlanta, Georgia 30302-5010, USA.