BOOK REVIEWS is in some way more appropriate. 1 believe that the view that female scientists are bet- ter suited to study other females (from our own or from other species), and more pre- pared to redress the biases of early studies, simply perpetuates the view that both sexes are inherently biased in the ways they do science. If they are, both must be wrong and, sadly, two wrongs don't make a right. If our personal (or ideological) views influence the way in which we interpret the natural world, the scientific method is there to help us out. The common theme of the book is the study of human female life history in an evolu- tionary context, and in order to do this much emphasis is put on explaining our roots as female mammals and primates. The prob- lem arises with the definition of life history itself. Fedigan lucidly explains in her chap- ter the different meanings that 'life history' has to biologists and to social scientists. In the biological sciences, life history theory attempts to relate specific ontogenetic and reproductive traits to population dynamics and evolutionary consequences. For social scientists, a life history is a biographical ac- count which focuses on the subject's view of what is important about his/her own life. Such different starting points obviously lead to different methodologies, with biologists using quantitative analyses of large sam- ples, and social scientists focusing on case- studies. The book covers studies of non- primate mammals, non-human primates and humans, and the authors come from very different backgrounds. The result is a blend of approaches in which hypotheses derived from theoretical frameworks as diverse as evolutionary theory, cultural anthropology and, in a few cases, feminist theories are all lumped together. Despite the effort placed on giving the book an evolutionary flavour, life history theory is not seen by the editors as entirely appropriate to the study of long lived and socially complex mammals such as primates. Their argument revolves around three main points. (1) The concept of 'trade-off' is not useful because the idea that energy cannot be used for two life processes at the same time may be handy when working on math- ematical models, but does not reflect what real animals actually do. It is also argued that the concept of trade-offs mistakenly assumes a consistent level of energy and time avail- able to the organism. (2) Individuals do not use long-term planning in making decisions; thus, trade-offs such as those between cur- rent and future reproduction are not poss- ible. (3) Life history theory has put too much emphasis on reproductive events and has undervalued survival features. In my opinion, while there are some grounds for point (3), points (1) and (2) are the result of a misunderstanding of life his- tory theory. Life history theory does not as- sume that animals cannot do 'many things simultaneously', it merely assumes that the amount of energy invested in one type of ac- tivity will influence how much energy is left for other activities. The fact that different individuals may have different energy bud- gets has been recognized for quite some time as the main reason why correlational studies of trade-offs often do not yield the expected negative relationships (high-quality individ- uals may invest more in reproduction and still suffer no costs, while low-quality in- dividuals may pay a high price for a small investment). In relation to point (2), there seems to be some confusion about what 'decision- making' means. In an evolutionary context, decision-making does not imply awareness on the part of the individual, and the fact that individuals make immediate decisions on a day-to-day basis does not negate the possi- bility that reproductive costs may be a selec- tive force strong enough to shape life history patterns. Further misinterpretations of life history theory are common throughout the book, such as the claim that delays in repro- duction challenge 'conventional life history models'. Contrary to this view, it is life his- tory theory that better explains such delays. In more general terms, a recurrent idea throughout the book is that life history models cannot account for the complexity of primate lives, and that more emphasis should be put on the study of 'whole organ- isms and whole lives' or 'real animals living real lives'. I wholly agree with the idea that there is an urgent need for more longitudi- nal studies on known individuals, but the point is not new. Many authors seem to feel that the degree of complexity of primate lives, together with the degree of inter-indi- vidual variability, makes quantitive analy- ses worthless. It is said, for example, that 'individual lives often become abstractions as researchers reduce their data to average ages for life history markers' and that 'some appear to have little interest in the animals themselves and prefer to ponder the theo- retical questions of how monkeys should behave'. My feeling is that this aversion to quantitative analyses greatly limits the suc- cess of the editors' attempts to differentiate the book's approach from that of the social sciences by adopting an evolutionary per- spective. Every researcher, like myself, who has studied primates has been genuinely impressed by the intricacies of their lives. However, I believe that rigorous hypothesis testing should be the rule, even in primate studies (even in women studies!). I say this, of course, because I am a biologist. Montserrat Gomendio Depto de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales (CSlC), Jos6 Gutierrez Abascal 2, 28006 Madrid, Spain The language of diversity The Evolution of Social Behaviour in Insects and Arachnids edited by J.C. Choe and B.J. Crespi Cambridge University Press, 1997. $120.00/£90.00 hbk, $47.50/£32.50 pbk (xiv + 541 pages) ISBN 0 521 5808 5 / 0 521 58977 0 The Evolution of Mating Systems in Insects and Arachnids edited by J. C Choe and B.J. Crespi Cambridge University Press, 1997. $100.00/£80.00 hbk, $44.95/£29.95 pbk (ix + 387 pages) ISBN 0 521 58029 3 / 0 521 58976 2 p ossessing these two handsomely pro- duced volumes is like possessing Aladdin's magic lamp. Flip through them and sure enough the genie (also known as the in- dex in our circles) will take you to wonder- ful, unheard-of and even amorous worlds. You may take your pick- from parental care in cockroaches to sex among cannibals in jumping spiders.., it's an endless menu! But you do need the genie to guide you through- over 900 pages of double-column fine print is not exactly meant for cover to cover reading. A particularly striking feature of the vol- ume on social behaviour is that it has almost no material on the standard, well worked- out wasp, higher ant and honey bee systems that form the basis of much of the current theoretical work on the evolution of social behaviour. This would be a serious weak- ness if one were to use it to give students an overview of the current state of insect socio- biology. But since much has been written on these matters, the fact that this volume covers so much obscure and uncharted ter- ritory is really to be seen as a great strength. Another notable feature of both volumes is the extent to which phylogenetic and often explicit cladistic analysis is used to buttress evolutionary arguments. This was almost unheard of just a few years ago- it is good to see some fashions spread so fast. It seems legitimate to ask what general lessons one has learnt from reading these volumes, either about social or about mating behaviour in insects and arachnids, if not in animals in general. Here there is a serious problem - but believe me, it's no one's fault. Just as physicists exploring the ultimate laws of nature are debating the virtues of dream- ing about a final theory 1, biologists are also in a dilemma. In the 1950s we began to shed our 'stamp collector' image and profess an in- terest in uncovering general laws of biology 122 Copyright © 1998,Elsevier ScienceLtd. All rights reserved. 0169-5347/98/$19.00 TREE voL 13, no. 3 March 1998