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Individuals respond differently to environmental stresses, and often a subpopulation will respond more adaptively than the rest. The analogy with experiments on genetic assimilation suggests that such individuals are likely to share the genes responsible for their adaptive response. If the environmental stress in a social species is the presence of an innovative animal, the adaptive response may be imitation of the innovator by a subpopulation of individuals sharing genes responsible for this capacity. Small increments in the fitness of many such individuals may add up to a substantial selection pressure for the underlying genes. Since learning and imitation are not unitary abilities, but in all probability depend on underlying “computational elements,” analogous to the instruction set of a computer, “assimilative” selection of this sort may constitute a positive feedback process that continually favors genes that add to the population’s store of such elements. This hypothesis is consistent with such puzzling features of human social behavior as the enormous amount of time devoted to social intercourse and the disproportion between human intelligence and the demands placed upon it in primitive cultures. It is also compatible with the evolution of intelligence and a large brain size in non-tool-using social species such as whales and dolphins.

The twin searches for animal intelligence and its neural counterparts have been dominated by a model that predicted a unilinear, hierarchical progression from simpler intellectual abilities to more complex abilities and from simpler brains to more complex brains. This model has produced a number of baffling inconsistencies and paradoxes for investigators who sought a smooth progression of increased behavioral performance or increased brain complexity among animals selected to represent stages in human evolution. On the other hand, a model based on the evolutionary principles of divergence and adaptation can deal more readily with the nonlinearities observed in both the behavioral data and the neuroanatomical data.

At the end of a lengthy survey of the comparative mental powers of man and other animals, Darwin (1871) concluded that “the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind.” Some may wish to argue that differences of degree will lead to differences of kind, but almost no biologist would now question Darwin’s main point, which was that man’s mind, including those aspects that we call intelligence, has evolved. Such universal agreement, testimony to the power of the notion of evolution and the generality of the intuition as to what intelligence is, contrasts sharply with our lack of understanding as to the way in which this has occurred. In part this is a result of difficulties in interpretation of one of the disciplines that lies at the heart of the issue, viz. comparative psychology. In part it is because of the restrictive way in which the whole problem of the evolution of intelligence has been viewed. An evolutionary epistemological approach to intelligence sheds some light on both matters.

It is often assumed that the evolution of intelligence is inevitable, given the self-organizing seen in dissapative systems and the gradual shaping-up of Darwinism. While compound-interest reasoning suggests that small advantages will eventually triumph, eventually may be a very long time: there are few examples of rapid brain growth, suggesting that “smarter-is-better” is not a potent force for evolution. Fast tracks to complexity may be much more important than the slow-but-predictable paths (especially given the “windows of opportunity” in the life cycle of a planet).

Evolution theory as well as evolutionary epistemology rejected from the beginning the idea of a throughgoing causality, leading to deterministic systems. Especially F. Wuketits1 in Biologie und Kausalitat demanded for biological and evolutionary systems a new model of causation. This model should explain functional and mutual causation in biological systems, where even circular and cybernetical causation very often occur. Such a model of “evolutionary causation” is built up step by step in this chapter, based on a detailed analysis of statistical causality or causality1, described elsewhere by the author.2 For such a purpose, classical causality (here called causality2), which has been rejected by most of the evolutionists, will be defined in a minimodel. It will be compared to, and contrasted with a model of statistical causation which, together with system-theoretical conditions, can be used successfully as a new model of causation for evolution. The difference between classical causality (causality2) and statistical evolutionary causality (causality1) begins with the predictions. Classically causal theories, such as celestial mechanics, predict future events and behaviour of individuals in social theories in a fictitious sense; for example the individual i will be born tomorrow at 7:15 and will die at the same month and day 77 years later at 22:10. Predictions from theories, based on statistical causality (causality1), are fuzzy intervals which include, and allow the individual, a certain leeway in acting or of random variation in his behaviour.

The main contribution of the fossil record concerning the evolution of intelligence, as I perceive it, is the time perspective: the time depth.

THE problem of the evolution of intelligent behaviour has recently achieved publicity1 in relation to work on the learning abilities of various vertebrates2. Over the past three years I have developed a general theory of the evolution of intelligence from, and within the framework of, an instinct system of Lorenz–Tinbergen type3. This theory is of wider scope than any which could be advanced on the basis of the present theories of learning; it can, it is felt, accommodate most of the ‘learning theory’ views; and it appears to provide a context for the understanding of a considerable variety of other phenomena. An extended account and discussion of this general theory of the evolution of intelligence is being offered for publication elsewhere—but a very brief preliminary account appears desirable, to stimulate interdisciplinary appraisal and discussion.

The use and manufacture of tools have been considered to be cognitively demanding and thus a possible driving factor in the evolution of intelligence. In this study, we tested the hypothesis that enhanced physical cognitive abilities evolved in conjunction with the use of tools, by comparing the performance of naturally tool-using and non-tool-using species in a suite of physical and general learning tasks. We predicted that the habitually tool-using species, New Caledonian crows and Galápagos woodpecker finches, should outperform their non-tool-using relatives, the small tree finches and the carrion crows in a physical problem but not in general learning tasks. We only found a divergence in the predicted direction for corvids. That only one of our comparisons supports the predictions under this hypothesis might be attributable to different complexities of tool-use in the two tool-using species. A critical evaluation is offered of the conceptual and methodological problems inherent in comparative studies on tool-related cognitive abilities.

Terrence Deacon’s “The Symbolic Species” came out in 1997 and became an important participant in the renewed focusing upon the issue of the origin of man. The basic Darwinian framework agreed upon by all serious research since early 20C had left the important problem of accounting for the evolution of man’s special intellectual abilities, including human language, as compared to other higher animals in general and man’s primate relatives specifically. The many competing theories of the origins of language along with the lack of empirical evidence to support either of them had, for many years, made speculations upon language origins obsolete – but with the increasing amount of knowledge about man’s genetic evolution, historical linguistics, cognitive science, neuroscience, the archeology of early human migrations etc. created a new platform for taking up this old issue. Deacon’s proposal was fourfold – based upon the combination of an evolutionary, a semiotic, a neurological, and an anthropological hypothesis. The evolutionary hypothesis was based upon so-called “Baldwinian” evolution – after the American psychologist James Mark Baldwin: the idea that in social species with individuals possessing a certain degree of ontogenetic learning abilities, new, acquired capabilities may assume a large degree of selective advantage for those individuals able to learn them. Thus, seemingly Lamarckian effects of inheritage of acquired characters may occur within a completely Darwinian framework: the acquired capabilities are not inherited, but the possession of them in some individuals provide a large selection advantage over those who have less ability to learn them. The example chosen in Deacon was, of course, human language: speakers will be strongly favoured at the expense of non-speakers, and thus the appearance of early, primitive language will speed up the process of evolution, eventually making the evolution of language and the evolution of the human brain two aspects of one basic process with intense feed-back between the two.

The competition for power in a complex social world is hypothesized to be a driving force in the evolution of intelligence. More specifically, power may be obtained not only by brute force but also by social strategies resembling human politics. Most empirical evidence comes from primate studies that report unprovoked aggression by dominants to maintain power by spreading fear and third-party interventions in conflicts. Coalitionary support has also been described in other animals and is often linked to social bonding. As coalitions can lead to a gain in power and fitness benefits, individuals may try to prevent coalitionary support or indirectly prevent others from forming social bonds that might lead to coalitions. Although there is some empirical evidence that coalitionary support can be manipulated, little is known about the indirect strategy. We show here that wild ravens (Corvus corax) regularly intervene in affiliative interactions of others even though such interventions are potentially risky and without immediate benefits. Moreover, the identities of both interveners and intervened pairs are not randomly distributed. Ravens with existing ties initiate most interventions, and ravens that are creating new ties are most likely to be the targets of interventions. These patterns are consistent with the idea that interventions function to prevent others from forming alliances and consequently becoming future competitors. We thus show previously undescribed social maneuvers in the struggle for power. These maneuvers are likely to be of importance in other social species as well.

The social brain hypothesis (SBH) posits that the demands imposed on individuals by living in cohesive social groups exert a selection pressure favouring the evolution of large brains and complex cognitive abilities. Using volumetry and the isotropic fractionator to determine the size of and numbers of neurons in specific brain regions, here we test this hypothesis in African mole-rats (Bathyergidae). These subterranean rodents exhibit a broad spectrum of social complexity, ranging from strictly solitary through to eusocial cooperative breeders, but feature similar ecologies and life history traits. We found no positive association between sociality and neuroanatomical correlates of information-processing capacity. Solitary species are larger, tend to have greater absolute brain size and have more neurons in the forebrain than social species. The neocortex ratio and neuronal counts correlate negatively with social group size. These results are clearly inconsistent with the SBH and show that the challenges coupled with sociality in this group of rodents do not require brain enlargement or fundamental reorganization. These findings suggest that group living or pair bonding per se does not select strongly for brain enlargement unless coupled with Machiavellian interactions affecting individual fitness.

Von Bonin discusses the evolution of the human brain from the anthropological point of view. He gives a critical review of the cranial and somatometric indices in different orders of primates. Of the three main groups of primates—hominidae, man, anthropoid apes—"none of the living primates is in direct ancestral line of man; they are all side issues, as it were." Of the hominidae. the Neanderthal group, scattered widely over the Eurafrasian land-mass, is farthest removed from the modern man, although "the earlier representatives of this group appear to have been closer to the main stream of human evolution than the latter ones..." The information on the catalogue of behavioral patterns ("culture") of the hominidae is meager. The Upper Paleolithic men "were, to all intents and purposes, modern men"; they manufactured implements, spoke, and drew pictures on the walls of their caves, ie, symbolized their internal experiences in symbolic abstractions of

It is no accident that the misreading of Congreve's "Music hath charms to soothe the savage breast" that appears in my title has become so popular. The nature of music's power over animals has long concerned humanssome as a philosophical matter, others, like the snake charmers, as a purely practical one. In the history of musical aesthetics there are at least three principal ideas about music's influence over animals. Some theorists have put forth the idea that all music is saturated with a divine power whose ethos affects the spirits of all creation, whether man or beast, alike. Responding to this conception, others have suggested that music is a species of language and as such has meaning for man alone. Our love of music and our appreciation for it is simply part of what sets us off from the insensitive brute creation. In this version of music's power, age-old legends of animal attraction to music must be taken figuratively. Finally, some philosophers, particularly in the modern age, have postulated a theory of music as a human art, again, akin to language, but one that nevertheless arose with the evolution of intelligence. Music, in this view, appeals to rational processes, and since animals are links in the chain of reasoning beings, they are capable to varying degrees of enjoying and even judging music. In this final version of music's power, animals have not only the faculties but even the taste for certain types of music. An examination of the diverse historical manifestations of each point of view reveals not only the way humans think of music, but also how they think of themselves and their place in the hierarchy of the cosmos. Tales of animal attraction to music appear in nearly every culture. The most familiar legend in the Western world, of course, is the myth of Orpheus. The Thracian poet, so goes the tale, received his lyre from Apollo

Much of sociology today is concerned with the study of inequalities, of which inequality between the sexes is one aspect. I wish to argue the case that the study of sexual inequality has thrown up ideas which help in the understanding of all kinds of structured inequality as well as that between men and women. Briefly, my case is that four key factors can be used to understand woman's position in society, and that three of them are necessary to the analysis of social stratification in general. The three common factors are scale, density of population and level of technology, but I will begin with the consideration of the factor peculiar to the analysis of sexual inequality, the impact on social structure of the fact of infantile dependence. The biological evolution of the human species has been towards greater intelligence and correlative loss of innately patterned behaviour. The human infant has an enormous capacity for learning, but while learning, an enormous dependence on adults for survival and training. Such an evolution of intelligence must have been matched by an evolution of strong drives to nurture and train the young, otherwise the substitution of learning capacity for programmed behaviour would have had no survival advantages, rather the reverse. It seems reasonable to suppose that the innate caring response of adult to young would evolve, together with intelligence, in both sexes equally, and that it would be triggered off in each individual's life by the presence of dependent infants, and be shaped, reinforced and particularized by interaction with particular dependent infants. Given the physiology of reproduction, this nurturant response is likely to be most strongly evoked and reinforced in the biological mother, who through pregnancy, childbirth and suckling, must be most open to the signals of the infant for food, love and care. Therefore it is not contradictory to my hypothesis of equal endowment of the sexes with the capacity and desire to nurture the young that, in fact, in every society the main work of child-care has devolved on the women. But a problem is raised when we realize that child-care has been mostly women's work not just as a matter of practice and convenience, but as a matter of social morality. Not only is women's care of young children morally approved of, but men's participation in such tasks is frequently derided, if not actually tabooed. Yet it follows from my assumption of a poten

The writer of this small monograph is one of the few persons trained in both anthropology and neurology. The book treats the evolution of the brain from Australopithecus to modern man. It does not attempt to go anterior to Australopithecus , but touches upon a few points in the evolution of the brain prior to the primate stage. Studied here are the final steps in the evolution of the human brain, neglecting the contemporary great apes which must vary considerably from the fossil forms through which man went. Considerable data are given by the author to show that none of the living primates is in the direct ancestral line. Chapter 2 presents a summary discussion of the fossil forms with which the book deals— Australopithecus, Sinanthropus-Pithecanthropus, Solo man and Neanderthal man—as an introduction to the description of their endocranial casts in chapter 3. The author notes that cranial capacity is not