Evolution of Human Behavior is the first text to synthesize and compare the major proposals for human behavioral evolution from an anthropological perspective. Ideal for courses in the evolution of human behavior, human evolutionary ecology, evolutionary psychology, and biological anthropology, this unique volume reviews a wide array of approaches on how and why humans evolved behaviorally.

.Evolutionary analysis focuses on how genes build organisms with different strategies for engaging and solving life’s challenges of survival and reproduction. One of those challenges is competing with conspecifics for limited resources including reproductive opportunities. This article will suggest that there is now good evidence for considering two dimensions of social competition. First, we will label antisocial strategies, to the extent that they tend to be self-focused, threat sensitive and aggressive, as well as using tactics of bulling, threatening, intimidating or (...) even injuring/killing competitors. Their strategic goal is to stimulate fear-inhibition, flight or submissive compliance in subordinates. Such strategies turn off and inhibit care and affiliative social interactions and motivation and they can be enacted by parents, teachers and leaders. The social signals emitted stimulate various aspects of threat processing in recipients, create stressful and highly stratified groups with a range of detrimental psychological and physiological effects. Second, in contrast, prosocial strategies seek to create relaxed and secure social interactions that enable sharing, cooperative and mutually supportive and beneficial relationships. The friendly and low/no threat social signals emitted in friendly cooperative and affiliative relationships stimulate physiological systems (e.g., oxytocin, the vagus parasympathetic system) that down regulates threat processing, enhances the immune system, facilitates frontal cortical processes and general wellbeing. This article reviews the literature pertaining to the evidence for these two dimensions of social engagement. (shrink)

In late September 1838, Darwin read Malthus's Essay on Population, which left him with “a theory by which to work.”115 Yet he waited some twenty years to publish his discovery in the Origin of Species. Those interested in the fine grain of Darwin's development have been curious about this delay. One recent explanation has his hand stayed by fear of reaction to the materialist implications of linking man with animals. “Darwin sensed,” according to Howard Gruber, “that some would object to (...) seeing rudiments of human mentality in animals, while others would recoil at the idea of remnants of animality in man.”116 With this link closed, Darwin hung the materialist chain around his own neck, where it rested most uncomfortably. Stephen Gould, supporting Gruber's argument, finds evidence for this reconstruction in Darwin's M and N notebooks, whichinclude many statements showing that he espoused but feared to expose something he perceived as far more heretical than evolution itself: philosophical materialism-the postulate that matter is the stuff of all existence and that all mental and spiritual phenomena are its by-products. No notion could be more upsetting to the deepest traditions of Western thought than the statement that mind-however complex and powerful-is simply a product of brain.117The proferred hypothesis suggests, then, that Darwin was acutely sensible of the social consequences of equating men with animals and therefore mind with brian, and that he thus shied from publically revealing his views until the intellectual climate became more tolerant.The history I have examined makes this hypothesis implausible. Even if Darwin warily explored the implications of his emerging theory in his notebooks, his subsequent study of Fleming, Wells, Brougham, and Kirby should have quieted any trepidation. If these natural theologians did not flinch at seeing human reason prefigured in the mind of a worm, should Darwin have? Moreover, he recognized in his M notebook that the thesis of evolutionary continuity between men and animals did not require an explicit avowal of his conviction that brain was the agent of thought.118 And in any case, his materialism was of a rather benign sort; at least he so expressed it in an annotation in Abercrombie's Inquiries concerning the Intellectual Powers (1838): “By materialism I mean, merely the intimate connection of thought with form of brain — like kind of attraction with nature of element.”119 This belief would have held little terror for British intellectuals, who were quite familiar — some even comfortable-with Locke's anti-Cartesian argument that there was nothing contradictory in supposing God could make matter to think.120 Finally, even if the intellectual atmosphere of early nineteenth-century Britain were inhospitable to Darwin's brand of materialism, there is little reason to believe he breathed a different air at mid-century while preparing his manuscript.That Darwin should not have feared suspicions of materialism, of course, does not mean that he did not. But I think there were other, more persistent sources of anxiety that kept him from rushing to publish: namely, the several conceptual obstacles he had to overcome if his theory of evolution by natural selection were to be made scientifically acceptable. Prominent among these were the problems surrounding his changing notions of instinct.The inertia of his older ideas about instinct at first made it hard for Darwin to gauge how far the theory of natural selection might be applied to behavior. By the early 1840s he finally felt ready to meet the challenge of the natural theologians by providing a naturalistic explanation for the wonderful instincts of animals. In his “Essays” of 1842 and 1844 one sort of instinct is, however, not considered-that of neuter insects. Yet Darwin seems to have appreciated the difficulties such instincts entailed at least by 1843, when he read Kirby and Spence. He simply required time to work out a solution to a problem he initially perceived as “fatal to my whole theory.” Even while writing the “Species Book” in the summer of 1857, he was still juggling several possible solutions compatible with natural selection. It was only a short time before he actually turned to work on the Origin of Species that he appears to have settled on a single explanation for the difficulties posed by the instincts of worker bees and ants. The force of his theory of community selection snapped the last critical support of the creationist hypothesis and, conveniently enough, also fractured the generalized Lamarckian account of the evolution of behavior. These results were worth waiting for. (shrink)

While many philosophers agree that evolutionary theory has important implications for the study of ethics, there has been no consensus on what these implications are. I argue that we can better understand these implications by examining two related yet distinct issues in evolutionary theory: the evolution of our moral beliefs and the evolution of cooperative behavior. While the prevailing evolutionary account of morality poses a threat to moral realism, a plausible model of how altruism evolved in human (...) beings provides the grounding for a research program that focuses on achieving some of the more practical goals shared by ethicists. †To contact the author, please write to: Department of Political Science, Economics, and Philosophy, College of Staten Island/City University of New York, 2800 Victory Blvd., Staten Island, NY 10314; e‐mail: [email protected]. (shrink)

In this paper I distinguish and characterize two strategies, both prominent in contemporary biology, for investigating the evolution of behavior. The ‘Lorenzian Strategy’ is taxon-focused, holistic, and particularistic, and relies heavily on naturalistic observation as well as careful experimental manipulation of target systems; it tends to produce detailed knowledge of concrete historical instances of the evolution of behavior in particular lineages. The ‘Analytic Strategy’ is principle-focused, generative, and taxonomically universal; it relies on the development of mathematical (...) principles (simple analytic models) of the evolution of behavior at an abstract level, and uses experimentation to garner support for the empirical relevance for these. The strategies hence employ different methods and produce different sorts of knowledge, hence they are neither inconsistent nor redundant, but complementary, and indeed they both play important roles in the contemporary biology of animal behavior. (shrink)

Self-medication behaviour is the use of natural materials or chemical substances to manipulate behaviour or alter the body’s response to parasites or pathogens. Self-medication can be preventive, performed before an individual becomes infected or diseased, and/or therapeutic, performed after an individual becomes infected or diseased. We summarized all available reports of self-medication in mammals and reconstructed its evolution. We found that reports of self-medication were restricted to eutherian mammals and evolved at least four times independently. Self-medication was most commonly (...) reported in primates. Detailed analyses of primates suggest that self-medication is a life-history trait associated with body size, absolute brain size and longevity, but we found no support for the hypothesis that self-medication evolved to reduce the costs of social living. Large, longer-lived species might thus benefit uniquely from self-medication. (shrink)

The current project introduces a general theory and supporting models that offer a plausible explanation and viable mechanism for generating and perpetuating prosocial behavior. The proposed mechanism is preferential detachment and the theory proposed is that agents utilizing preferential detachment will sort themselves into social arrangements such that the agents who contribute a benefit to the members of their group also do better for themselves in the long run. Agents can do this with minimal information about their environment, the (...) other agents, the future, and with minimal cognitive/computational ability. The conclusion is that self-organizing into groups that maintain prosocial behaviors may be simpler and more robust than previously thought. The primary contribution of this research is that a single, simple mechanism operating in different contexts generates the conceptually distinct prosocial behaviors achieved by other models, and in a manner that is more amenable to evolutionary explanations. It also bears importantly on explanations of the evolution of our moral experiences and their connection with prosociality. (shrink)

Introduction, W G Runciman Social Evolution in Primates: The Role of Ecological Factors and Male Behaviour, Carel P van Schaik Determinants of Group Size in Primates: A General Model, R I M Dunbar Function and Intention in the Calls of Non-Human Primates, Dorothy L Cheney & Robert M Seyfarth Why Culture is Common, but Cultural Evolution is Rare, Robert Boyd & Peter J Richerson An Evolutionary and Chronological Framework for Human Social Behaviour, Robert A Foley Friendship and the (...) Banker?s Paradox: Other Pathways to the Evolution of Adaptations for Altruism, John Tooby & Leda Cosmides The Early Prehistory of Human Social Behaviour: Issues of Archaeological Inference and Cognitive Evolution, Steven Mithen The Emergence of Biologically Modern Populations in Europe: A Social and Cognitive ?Revolution??, Paul Mellars Responses to Environmental Novelty: Changes in Men?s Marriage Strategies in a Rural Kenyan Community, Monique Borgerhoff Mulder Genetic Language Impairment: Unruly Grammars, M Gopnik, J Dalalakis, S E Fukuda, S Fukuda & E Kehayia The Emergence of Cultures among Wild Chimpanzees, Christophe Boesch Terrestriality, Bipedalism and the Origin of Language, Leslie C Aiello Conclusions, John Maynard Smith. (shrink)

The two main theories of food-associated calls in animals propose functions either in cooperative recruitment or competitive spacing. However, not all social animals produce food calls and it is largely unclear under what circumstances this call type evolves. Sooty mangabeys do not have food calls, but they frequently produce grunts during foraging, their most common vocalisation. We found that grunt rates were significantly higher when subjects were foraging in the group’s periphery and with small audiences, in line with the cooperative (...) recruitment hypothesis. In a subsequent field experiment we presented highly desired food items and found that discovering individuals called, unless harassed by competitors, but that the calls never attracted others, confirming that the grunts do not convey any information referential to food. Our data thus suggest that the evolution of cooperative food calling is a two-step process, starting with increased motivation to vocalise in the feeding context, followed by the evolution of acoustic variants derived from context-general contact calls. This evolutionary transition may only occur in species that feed on clumped, high-quality resources where social feeding is competitive, a condition not met in sooty mangabeys. (shrink)

This book highlights the recent re-emergence of Edward Westermarck's work in modern approaches to morality and altruism, examining his importance as one of the founding fathers of anthropology and as a moral relativist, who identified our moral feelings with biologically-evolved retributive emotions. Questioning the extent to which current debates on the relationship between biology and morality are similar to those in which Westermarck himself was involved, the authors ask what can be learnt from his arguments and from the criticism that (...) he encountered. Drawing on Westermarck's manuscripts and papers as well as his published work, the authors show the importance of situating debates, whether modern or classical, in their correct methodological and philosophical context. This volume is a rigorous assessment of the ways in which morality is connected with human biological nature. It plays close attention to the development of debates in this field and will appeal to scholars of sociology, anthropology and philosophy. (shrink)

Understanding the link between brain evolution and the evolution of distinctive features of modern human cognition is a fundamental challenge. A still unresolved question concerns the co-evolution of tool behavior (i.e., tool use or tool making) and language. The shared neurocognitive processes hypothesis suggests that the emergence of the combinatorial component of language skills within the frontal lobe/Broca's area made possible the complexification of tool-making skills. The importance of the frontal lobe/Broca's area in tool behavior (...) is somewhat surprising with regard to the literature on neuropsychology and cognitive neuroscience, which has instead stressed the critical role of the left inferior parietal lobe. Therefore, to be complete, any version of the shared neurocognitive processes hypothesis needs to integrate the potential interactions between the frontal lobe/Broca's area and the left inferior parietal lobe as well as their co-evolution at a phylogenetic level. Here, we sought to provide the first elements of answer through the use of the massive deployment framework, which posits that evolutionarily older brain areas are deployed in more cognitive functions (i.e., they are less specific). We focused on the left parietal cortex, and particularly the left areas PF, PGI, and anterior intraparietal (AIP), which are known to be involved in tool use, language, and motor control, respectively. The deployment of each brain area in different cognitive functions was measured by conducting a meta-analysis of neuroimaging studies. Our results confirmed the pattern of specificity for each brain area and also showed that the left area PGI was far less specific than the left areas PF and AIP. From these findings, we discuss the different evolutionary scenarios depicting the potential co-evolution of the combinatorial and generative components of language and tool behavior in our lineage. (shrink)

Understanding the link between brain evolution and the evolution of distinctive features of modern human cognition is a fundamental challenge. A still unresolved question concerns the co-evolution of tool behavior (i.e., tool use or tool making) and language. The shared neurocognitive processes hypothesis suggests that the emergence of the combinatorial component of language skills within the frontal lobe/Broca's area made possible the complexification of tool-making skills. The importance of the frontal lobe/Broca's area in tool behavior (...) is somewhat surprising with regard to the literature on neuropsychology and cognitive neuroscience, which has instead stressed the critical role of the left inferior parietal lobe. Therefore, to be complete, any version of the shared neurocognitive processes hypothesis needs to integrate the potential interactions between the frontal lobe/Broca's area and the left inferior parietal lobe as well as their co-evolution at a phylogenetic level. Here, we sought to provide the first elements of answer through the use of the massive deployment framework, which posits that evolutionarily older brain areas are deployed in more cognitive functions (i.e., they are less specific). We focused on the left parietal cortex, and particularly the left areas PF, PGI, and anterior intraparietal (AIP), which are known to be involved in tool use, language, and motor control, respectively. The deployment of each brain area in different cognitive functions was measured by conducting a meta-analysis of neuroimaging studies. Our results confirmed the pattern of specificity for each brain area and also showed that the left area PGI was far less specific than the left areas PF and AIP. From these findings, we discuss the different evolutionary scenarios depicting the potential co-evolution of the combinatorial and generative components of language and tool behavior in our lineage. (shrink)

ABSTRACTRecent research on moral dynamics shows that an individual's ethical mind-set moderates the impact of an initial ethical or unethical act on the likelihood of behaving ethically on a subsequent occasion. More specifically, an outcome-based mind-set facilitates Moral Balancing, whereas a rule-based mind-set facilitates Moral Consistency. The objective was to look at the evolution of moral choice across a series of scenarios, that is, to explore if these moral patterns are maintained over time. The results of three studies showed (...) that Moral Balancing is not.. (shrink)

Feed-forward Pavlovian conditioning can serve as a proximate mechanism for the evolution of social behavior. Feed-forward can provide the impetus for animals to associate other individuals' presence, and cooperation with them, with the acquisition of resources, whether or not the animals are genetically related. Other social behaviors such as play and grooming may develop as conditioned stimuli in feed-forward social systems.

Honeybees display a fascinating social behavior. The structural basis for this behavior, which made the bee a model organism for the study of communication, learning and memory formation, is the tiny insect brain. Neurons of the brain communicate via messenger molecules. Among these molecules, neuropeptides represent the structurally most‐diverse group and occupy a high hierarchic position in the modulation of behavior. A recent analysis of the honeybee genome revealed a considerable number of predicted (200) and confirmed (100) (...) neuropeptides in this insect.1 Is this quantity merely the result of advanced mass spectrometric techniques and bioinformatic tools or does it reflect the expression of more of these important messenger molecules, more than known from other insects studied so far? Our analysis of the data suggests that the social behavior is by no means correlated with a specific increase in the number of neuropeptides. Indeed, the honeybee genome is likely to contain fewer neuropeptide genes, neuropeptide paralogues and neuropeptide receptor genes than the solitary fruitfly Drosophila. BioEssays 29:416–421, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

Many researchers have assumed that punishment evolved as a behavior-modification strategy, i.e. that it evolved because of the benefits resulting from the punishees modifying their behavior. In this article, however, we describe two alternative mechanisms for the evolution of punishment: punishment as a loss-cutting strategy (punishers avoid further exploitation by punishees) and punishment as a cost-imposing strategy (punishers impair the violator’s capacity to harm the punisher or its genetic relatives). Through reviewing many examples of punishment in a (...) wide range of taxa, we show that punishment is common among plant and animal species and that the two mechanisms we describe have often been important for the evolution of punishment. (shrink)

Human beings possess external stores in which they put all sorts of goods to use them at some later time. In this paper we investigate this typically human adaptation using agent-based simulations. We show that the use of external stores explains many aspects of human life, allowing the agents to reduce their dependence on both the environment and the current state of their body and to be more efficient in extracting the energy contained in the environment. We analyse the spatial (...) behaviour of agents with external stores located in specific positions of the environment and we find that these agents tend to develop a sedentary life. We discuss how stores can be at the origin of many human mental and social phenomena such as the acquisition of a more extended temporal perspective, specialisation in producing different types of goods, and exchange of goods. (shrink)

Human beings possess external stores in which they put all sorts of goods to use them at some later time. In this paper we investigate this typically human adaptation using agent-based simulations. We show that the use of external stores explains many aspects of human life, allowing the agents to reduce their dependence on both the environment and the current state of their body and to be more efficient in extracting the energy contained in the environment. We analyse the spatial (...) behaviour of agents with external stores located in specific positions of the environment and we find that these agents tend to develop a sedentary life. We discuss how stores can be at the origin of many human mental and social phenomena such as the acquisition of a more extended temporal perspective, specialisation in producing different types of goods, and exchange of goods. (shrink)

We advocate for an integrative long-term perspective on time, noting that culture changes on timescales amenable to behavioral genetic study with appropriate design and modeling extensions. We note the need for replications of behavioral genetic studies to examine model invariance across long-term timescales, which would afford examination of specified as well as unspecified cultural moderators of behavioral genetic effects.

In a dynamic world, mechanisms allowing prediction of future situations can provide a selective advantage. We suggest that memory systems differ in the degree of flexibility they offer for anticipatory behavior and put forward a corresponding taxonomy of prospection. The adaptive advantage of any memory system can only lie in what it contributes for future survival. The most flexible is episodic memory, which we suggest is part of a more general faculty of mental time travel that allows us not (...) only to go back in time, but also to foresee, plan, and shape virtually any specific future event. We review comparative studies and find that, in spite of increased research in the area, there is as yet no convincing evidence for mental time travel in nonhuman animals. We submit that mental time travel is not an encapsulated cognitive system, but instead comprises several subsidiary mechanisms. A theater metaphor serves as an analogy for the kind of mechanisms required for effective mental time travel. We propose that future research should consider these mechanisms in addition to direct evidence of future-directed action. We maintain that the emergence of mental time travel in evolution was a crucial step towards our current success. (shrink)

Guided by neuroscience, animal behavior, evolution, philosophy, and psychology, Asma burrows deep into the human psyche to look right at the enigmatic but powerful engine that is our improvisational creativity—the source, he argues, of our remarkable imaginational capacity. How is it, he asks, that a story can evoke a whole world inside of us? How are we able to rehearse a skill, a speech, or even an entire scenario simply by thinking about it? How does creativity go beyond (...) experience and help us make something completely new? And how does our moral imagination help us sculpt a better society? As he shows, we live in a world that is only partly happening in reality. Huge swaths of our cognitive experiences are made up by “what-ifs,” “almosts,” and “maybes,” an imagined terrain that churns out one of the most overlooked but necessary resources for our flourishing: possibilities. Considering everything from how imagination works in our physical bodies to the ways we make images, from the mechanics of language and our ability to tell stories to the creative composition of self-consciousness, Asma expands our personal and day-to-day forms of imagination into a grand scale: as one of the decisive evolutionary forces that has guided human development from the Paleolithic era to today. The result is an inspiring look at the rich relationships among improvisation, imagination, and culture, and a privileged glimpse into the unique nature of our evolved minds. (shrink)

Biological evolution is often viewed narrowly as a change of morphology or allele frequency in a sequence of generations. Here I pursue an alternative informational concept of evolution, as preservation, advance, and emergence of functional information in natural agents. Functional information is a network of signs that are used by agents to preserve and regulate their functions. Functional information is preserved in evolution via complex interplay of copying and construction processes: the digital components are copied, whereas interpreting (...) subagents together with scaffolds, tools, and resources, are constructed. Some of these processes are simple and invariant, whereas others are complex and contextual. Advance of functional information includes improvement and modification of already existing functions. Although the genome information may change passively and randomly, the interpretation is active and guided by the logic of agent behavior and embryonic development. Emergence of new functions is based on the reinterpretation of already existing information, when old tools, resources, and control algorithms are adopted for novel functions. Evolution of functional information progressed from protosemiosis, where signs correspond directly to actions, to eusemiosis, where agents associate signs with objects. Language is the most advanced form of eusemiosis, where the knowledge of objects and models is communicated between agents. (shrink)

This article explores the normative nature of institutions. The starting point of my investigation is Kahneman, Knetsch and Thaler's notion of the reference transaction from which I derive a recursive relationship between normative judgements and social practices (i. e. regular, routinised actions in a social group), an implication of which I call the "self-justification of practices". Drawing on John Dewey, I demonstrate how prevailing practices influence normative standards and thus how institutions become normative entities. I then show how, despite the (...) conservative bias of normative standards, institutional change comes about. Finally, I enquire into the possibility of normative critique of prevailing practices and institutions. (shrink)

Aspects of human symbolic evolution are studied by scholars active in a variety of fields and disciplines in the life and the behavioral sciences as well as the scientific-philosophical, sociological, anthropological, and linguistic sciences. These fields and disciplines all take on an evolutionary approach to the study of human symbolism, but scholars disagree in their theoretical and methodological attitudes. Theoretically, symbolism is defined differentially as knowledge, behavior, cognition, culture, language, or social group living. Methodologically, the diverse symbolic (...) class='Hi'>evolution sciences establish their teachings upon diverging evolutionary biological schools and paradigms. This chapter reviews past and current research fields in human symbolic evolution for how they differentially implement tenets of the major evolution schools that were discussed in the previous chapter. Traditional evolutionary epistemology and biosemiotics bring in a mesoevolutionary outlook by drawing on early Darwinism and evolutionary developmental biology movements that emphasize the role of the organism in evolution. Communication studies instead originally take on a microevolutionary perspective by investigating how units of information are transmitted across generations through time. Only later do they integrate studies on meaning-making at the organismal level. Sociobiology complements a microevolutionary with a macroevolutionary outlook by implementing population genetic approaches, typical of the Modern Synthesis, into studies on individual and group behavior. The new symbolic evolutionary sciences build upon these traditions and include disciplines such as evolutionary psychology, evolutionary linguistics, evolutionary anthropology, evolutionary archaeology, evolutionary sociology, and evolutionary economics. Originally centered on implementing Darwinian selection theory, these fields are now including ecological and evolutionary developmental biology as well as reticulate evolutionary paradigms. As diverse in outlook and scope as they are, no discipline holds a privileged position over the other and all have made valuable contributions to our understanding of human symbolic evolution. (shrink)

Behavioral genetics and cultural evolution have both revolutionized our understanding of human behavior – largely independent of each other. Here, we reconcile these two fields under a dual inheritance framework, offering a more nuanced understanding of the interaction between genes and culture. Going beyond typical analyses of gene–environment interactions, we describe the cultural dynamics that shape these interactions by shaping the environment and population structure. A cultural evolutionary approach can explain, for example, how factors such as rates of (...) innovation and diffusion, density of cultural subgroups, and tolerance for behavioral diversity impact heritability estimates, thus yielding predictions for different social contexts. Moreover, when cumulative culture functionally overlaps with genes, genetic effects become masked, unmasked, or even reversed, and the causal effects of an identified gene become confounded with features of the cultural environment. The manner of confounding is specific to a particular society at a particular time, but a WEIRD (western, educated, industrialized, rich, and democratic) sampling problem obscures this boundedness. Cultural evolutionary dynamics are typically missing from models of gene-to-phenotype causality, hindering generalizability of genetic effects across societies and across time. We lay out a reconciled framework and use it to predict the ways in which heritability should differ between societies, between socioeconomic levels, and other groupings within some societies but not others, and over the life course. An integrated cultural evolutionary behavioral genetic approach cuts through the nature–nurture debate and helps resolve controversies in topics such as IQ. (shrink)

Using evolutionary game theory, I consider how guilt can provide individual fitness benefits to actors both before and after bad behavior. This supplements recent work by philosophers on the evolution of guilt with a more complete picture of the relevant selection pressures.

Here I briefly discuss some comparative data on social play behaviour in hope of broadening the array of species in which researchers attempt to study animal morality. I am specifically concerned with the notion of ‘behaving fairly'. In the term ‘behaving fairly’ I use as a working guide the notion that animals often have social expectations when they engage in various sorts of social encounters the violation of which constitutes being treated unfairly because of a lapse in social etiquette. I (...) will cash this out below in my discussion of social play behaviour. (shrink)

Behavior may be controlled by reactive systems. In a reactive system the motor output is exclusively driven by actual sensory input. An alternative solution to control behavior is given by “cognitive” systems capable of planning ahead. To this end the system has to be equipped with some kind of internal world model. A sensible basis of an internal world model might be a model of the system's own body. I show that a reactive system with the ability to (...) control a body of complex geometry requires only a slight reorganization to form a cognitive system. This implies that the assumption that the evolution of cognitive properties requires the introduction of new, additional modules, namely internal world models, is not justified. Rather, these modules may already have existed before the system obtained cognitive properties. Furthermore, I discuss whether the occurrence of such world models may lead to systems having internal perspective. (shrink)