Behaviour is a more complicated object for evolutionary explanation than physical characteristics and social behaviour is trickier than be-haviour in general. Social bebe-haviour involves fitness effects for more than one individual at a time and the selective environment of the evo-lution of social behaviour is in continuous change, which causes the evolutionary functionality of the behavioural trait to be in constant flux. The evolution of social behaviour became an object of systematic study only after a new framework of mathematical models was intro-duced in the 1960s and 1970s, particularly by William D. Hamilton (1964a & 1964b), Robert Trivers (1971 & 1974), and Edward O. Wilson (1975), who gave the field its name, sociobiology, and systematized it (see also Dawkins 1976 and Alcock 2003). Soon after this, the same explanatory models were applied to human social behaviour, with varying degrees of success (see Kitcher 1985 for a review and criticism of much of the early work). After the partial failure of these early at-tempts, as well as some failures in the sociobiological approach over-all, several different styles of evolutionary human sciences were de-veloped, dealing with social behaviour that ranged from the general basis of the socially tuned mind and cooperation to specific issues con-cerning, for example, family relations, mating, religion, morality, and so on.7
There is a tendency in evolutionary human sciences to be meth-odologically individualist and this is partly for good reasons. The early forms of what was known as group selection (e.g. Wynne-Ed-wards 1962) had serious problems in its unsupported, ambivalent as-sumptions about the “good of the group” and could not come up with
7 I will briefly review evolutionary human social sciences in chapter 4.
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a mechanism for group-level selection to overcome individual selec-tion (see Maynard Smith 1964; Williams 1966). The biggest problem was that there is always individual selection between the members of a group and therefore, if all individuals get the fitness benefits due to belonging to the group, individual selection overrides the group se-lection whenever individual and group sese-lection pull evolution in dif-ferent directions. If only behaviour that maximizes the individual fit-ness is selected, there is no need for group selection in models and explanations. Much of sociobiology aimed at showing how social evo-lution can be understood while staying in the individualist frame-work. An individual’s fitness, at least in an inclusive sense (which then became the “gene’s point of view” of evolution; see Dawkins 1976; Sterelny & Kitcher 1988), became the universal viewpoint for evolutionary explanations. Altruism became a central theoretical problem for sociobiology, but in most cases it was assumed that altru-istic behaviour could be explained through kin selection (Hamilton 1964a&b) as maximizing one’s own genes’ fitness through relatives that share the genes, or as reciprocal helping (Trivers 1971). In both cases, altruism was only “apparent” from the evolutionary point of view.
The renewed idea of group selection has since been re-introduced by a handful of biologists and philosophers (see for example Wilson 1975 & 1989; Sober 1984a; Heisler & Damuth 1987; Damuth & Heisler 1988; Goodnight et al 1992; Wilson & Sober 1994; Goodnight & Stevens 1997; Sober & Wilson 1998; Okasha 2006; Goodnight 2012). Some evo-lutionary human scientists (for example, Boyd & Richerson 1985 &
2005; Gintis 2000b; Henrich & Henrich 2007; Bowles & Gintis 2011) have taken this approach seriously, but it is still not a widely, let alone a universally, accepted idea. There are several good reasons for this:
the apparent weakness of group-level selection in competing with in-dividualist counter-selection, the possibility of alternative (seemingly) individualist models when group selection seems to take place, and difficulties in finding unequivocal empirical evidence for it (for exam-ple, Kerr & Godfrey-Smith 2002; West et al 2008; Gardner 2013). I will
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argue that some of the discussion on group selection is, after all the philosophical scrutiny over it, still somewhat ambiguous, and argue that group selection would be, in some of its senses, credible in the human context even if it was rare or non-existent elsewhere. But there are also human-specific concerns about the applicability of evolution-ary explanations to human social behaviour in the first place, given the plasticity of the human mind, the power of culture to guide behav-iour, and the novel complexity of human societies. I will not argue for the relevance of evolutionary approaches in this dissertation, but I will next discuss this topic and provide arguments for why such ap-proaches may at least be worth trying.
1.2.1. Evolutionary Explanations in Human Context
Humans are biological beings whose basic characteristics are products of an evolutionary process. These include human behaviour and cul-ture – they are biological phenomena. This claim does not imply any-thing specific as such, for example, about the freedom of the will; fix-edness or plasticity of behaviour, or its development; the range of pos-sible cultural variation in behaviour; the applicability of evolutionary models to contemporary human behaviour; or the relevance of prima-tology or any other field of biology to human social or behavioural sciences. All these issues depend on what kind of biological beings hu-mans are.8 The evolutionary origin of human social behaviour would be a theoretically important issue even if it did not have any conse-quences for any other scientific pursuits that build our understanding
8 Neither is this an issue about whether humans are “blank slates” or not (Pinker 2002). Human mind has gene-related evolved developmental tenden-cies that guide, skew, and constrain the psychological make-up we can end up having as the end result of psychological development, but this general fact alone leaves open a wide range of possibilities from innate, massively modular mind to high levels of developmental plasticity. I will return to these issues later.
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of ourselves. The knowledge of the origins and the naturalized version of “design” is an essential part of what can be called “naturalized phil-osophical anthropology”, a science-based (but not necessarily reduc-tionist) view of humanity, and of humans as “fundamentally social animals”, as it were. Whether or not the evolutionary approach has more concrete consequences for human sciences depends on what the actual evolution has produced. The evolutionary history of the human species is what determines how much our knowledge of this very his-tory helps us to understand the social behaviour of contemporary hu-man beings.
There is a range of theoretical possibilities on this issue. On one end of the spectrum, evolutionary history does not have any conse-quences for any other epistemic pursuits about human beings. On the other end, the evolutionary perspective is a central organizing princi-ple and a set of heuristics for generating fruitful research questions and hypotheses within other human sciences. Which theoretical pos-sibility is the actual case, is, however, something we cannot know be-fore the very research that evolutionary approaches are supposed to help. This is because of two things. First, given the epistemic con-straints we have in tracing our evolutionary history, figuring out the past involves finding out what has evolved: it involves not only theo-retical knowledge on evolutionary processes in general and evidence through fossils, but also some knowledge of the end-product, as well as comparative studies on the variation in contemporary humans and in our closest living relatives. Discovering our evolutionary history is dependent on our systematic knowledge of contemporary humans.
Second, we cannot know how useful the heuristics based on the evo-lutionary “reasons” for our behavioural dispositions are in the process of building this systematic image of humans in contemporary settings, except by comparing the speculations based on evolution and the even-tual empirical discoveries. We need to see where evolutionary specu-lations lead us, what we discover empirically, and how often the for-mer helps with the latter.
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In other words, whether evolutionary approaches are helpful for other fields of inquiry or not, is already a substantial hypothesis about what human beings are like and what their evolution was like, and this cannot be known prior to research. On one hand, we cannot draw the evolutionary picture without the systematic picture, and on the other hand, theoretical considerations alone, be they philosophical or evolutionary, cannot resolve the issue of how much help the evolu-tionary history provides us for drawing the systematic picture. Con-sequently, if we suspect evolutionary considerations to be useful in generating knowledge on human behaviour, we need to build both pictures – evolutionary and systematic – in close interaction. Since the usefulness of evolutionary approaches depends on what kind of be-ings we are, which is discovered through empirical research, and since we want to know whether the evolutionary approach is helpful in this empirical project or not, the only way to approach the question is through testing evolutionary ideas in empirical research. Hypotheses that are inspired by evolutionary considerations and the speculative history of our species may or may not turn out to be an important and fruitful part of this empirical project, but testing these ideas is the only way to know this.9 The ideas to be tested include both the known de-tails of the actual human evolutionary history and the knowledge about the kinds of causes that guide evolutionary processes in general for hy-pothesizing what psychological and social phenomena (and the prox-imate mechanisms producing those phenomena) could, could not, should, and should not exist. If this strategy for generating hypotheses turns to be successful, we have implicitly produced evidence for evo-lutionary history being important to understanding our contempo-rary selves.
The above is, in part, why I do not evaluate the evolutionary hu-man behavioural sciences as such but rather concentrate on some
9 This is a variant of the Lakatosian idea of how the core assumptions of re-search programmes get tested: not directly, nor by theoretical arguments, but through their usefulness in research (Lakatos 1970 & 1978).
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methodological issues of what this science should be like if it is going to be successful. Philosophers have contributed their criticism volubly (and deservedly) in general, and I have little new to add. Instead, I will try to make a positive contribution to the theoretical basis. Even if the evolutionary social science turns out to be impossible, the same issues will still turn up in the study of the “mere” evolutionary history of human sociality, and evolutionary history and its guiding princi-ples are interesting enough issues even as stand-alone questions. The topics I am exploring have consequences for this stand-alone project, at the least. They will be, when combined with direct empirical knowledge of human behaviour and psychology, a part of our under-standing of what human sociality and culture are in the first place.
Most scientific approaches to human behaviour are interested in proximate causes. The developmental perspective, however, is at least an important heuristic regarding what behavioural dispositions there can be (they need to be possible to develop, after all) and what external factors the individual is sensitive to. For example, all theories that pre-suppose culture to have something to do with differences in human behavioural dispositions also presuppose that some cultural entities (whatever they are) play a causal role in individual development. The evolutionary perspective, in turn, focuses on the history of the behav-ioural disposition on a population level. An evolutionary history of a trait is essentially a descriptive history, which includes, to some ex-tent, explanatory factors that tell us why certain behavioural disposi-tions exist in the population rather than some other disposidisposi-tions. At minimum, then, evolutionary knowledge increases our self-under-standing by telling us how the phenomena under investigation came to be, historically. This in turn may include understanding the con-straints and scope of the behaviour. At maximum, the evolutionary his-tory of a behavioural trait can highlight the function of behaviour in respect to its environment in a way that links certain environmental factors with the behaviour. If this is the case, the evolutionary perspec-tive tells us why the behavioural disposition under study is coupled with certain environmental stimuli (including stimuli in the social
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environment) and why certain environmental factors (including fac-tors in social and cultural environment) have the influence they have in the developmental process. This knowledge can also help us dis-cover the range of environmental variation in which the behaviour can be expected to emerge, by turning our attention to what is relevant in the environment (see Narvaez et al 2012 & 2014, for example).10 If some position at the maximal end of these possibilities proved to be true – if we could rely on the connections between environment, behaviour, and the evolutionary function to hold – then we could turn evolution-ary speculations into useful heuristics for hypothesizing about proxi-mate mechanisms and behavioural phenomena.
To use an example of human social intelligence to illustrate these ideas, an example of a “minimal” project would be something like some of the more general explanatory work on what is called “Mach-iavellian intelligence”11 (Byrne & Whiten 1988; Whiten & Byrne 1997;
10 There is a net of proximate causal factors (both internal and external to the individual) that bring about the external behaviour in the context of the actual behaviour. Another net of causal factors (both internal and external to the individual) guides the development of these behavioural dispositions. Yet an-other set of causal factors explains the evolutionary history of those disposi-tions and interacdisposi-tions between an individual and its environment in both the proximate causal context of behaviour and its development. Any causal factor of the same descriptive type (e.g. a specific feature of environment) may be an explanatory factor in all dimensions. For example, in the human context, a type of interaction with other human beings (including cultural transmission) may be a part of the causal environment of the actual behaviour, of the devel-opment of the behavioural dispositions, and of the selective environment dur-ing the evolution of behaviour to the extent that it is similar to the ancestral social environment. The functionality of a trait may depend on these factors to be the same. If the environment changes from the evolutionary context, the functionality, the development, or both may change as well.
11The basic idea of “Machiavellian intelligence” is that the roots of human so-cial intelligence (and primate intelligence in more general – the term was in-troduced by Frans de Waal (1982) for a chimpanzee social intelligence) lie in
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Byrne 1997; see also Corballis & Lea 1999). A “maximal” project on the same issue would be to use the knowledge of or speculations on the context of the evolutionary origins, the models related to that context, and the plausible predictions they generate, as a basis for directly test-able hypotheses on psychological capacities and biases, such as the evolution-based work on the “Wason Selection Task” (Wason 1966) and its connection to social adaptativeness in cheater detection (Cos-mides 1987; Cos(Cos-mides & Tooby 2005b).12 Both approaches may be val-uable at times – it is a trait-by-trait issue, not an issue with a general answer.
Even for the “mere” understanding of ourselves (or, the minimal contribution), the evolutionary perspective is not only an extra dimen-sion to our self-understanding, but a fundamental piece of knowledge to satisfy the intellectual curiosity that often drives scientific and phil-osophical pursuits. It makes things (that would stay either messy or mysterious without the evolutionary perspective) intelligible. As The-odosius Dobzhansky (1973) famously put it, “nothing in biology makes sense except in the light of evolution.” This quote should not be taken as a point about our inability to understand how the proxi-mate mechanisms work in biology without the evolutionary perspec-tive – we are perfectly capable of doing so – but the evolutionary per-spective enables us to make sense of why the things are the way they are. Where did the apparently purposeful, often holistic, design come from? Why are there dysfunctionalities and faults in this design, from an intelligent designer point of view, that tend to be similar in kind to
the evolutionary “arms race” of social cognitive capacities in the environment of social competition, politics, coalition building, and manipulation.
12The idea here is that the capacity to formally infer along the lines of a mate-rial implication has been selected for detecting cheaters of social norms or contracts and therefore is activated in contexts involving social norms, mak-ing the inference practically automatic in these contexts, whereas in non-social contexts people make mistakes and find the formally similar inference tasks much more difficult. This hypothesis has a number of testable consequences.
For criticism of the idea, see Davies et al 1995; Sperber & Girotto 2003.
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other such faults – often as if some parts were taken from another de-sign? Why are there clusters of characteristics across groups of species without any apparent reason for these characteristics to cluster? The same applies to human social behaviour to the extent that we can un-derstand it from an evolutionary point of view. When we can cast an evolutionary light on it, we start making more sense of it. For example, suppose we discovered the evolutionary origins of morality. That is, we could explain why we are interested in the categories of right and wrong in the first place, and why we feel that we need to act in ac-cordance with what we perceive to be right. This would deepen our understanding of ourselves even if it had no consequences for our moral practices or ethical theories – or even for our scientific under-standing of moral psychology. If we did not have even plausible spec-ulations about its origins, it would be mysterious and possibly, alt-hough not necessarily, a challenge to a naturalistic world view as well.13
1.2.2. Evolution as an Integrative Perspective
There is, however, a more important way in which evolutionary per-spective strengthens our understanding: scientific integration.14 Evolu-tionary perspective provides a framework for understanding how
13 Even a plausible speculation may do some important intellectual work on this even if we had no way to confirm our speculations. William Dray’s idea of how possible explanations in history proper was exactly that even though we cannot always provide verifiable explanations for historical events, we can make them intelligible by producing a narrative that makes them fit with what we know (Dray 1963; see also Persson 2012). The event or phenomenon under interest ceases to be a mystery or an anomaly, even if we do not know if the provisional explanation we give it is correct or not. I will briefly return to how possible explanations in chapter 3.
14 This is also discussed in Dobzhansky’s 1973 paper, although from a peda-gogical point of view.
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various properties of an organism and its behaviour are functionally related to each other. Consequently, this perspective makes intelligi-ble how the different fields of biology are related, through giving a perspective on how their explananda are related. This integrative
various properties of an organism and its behaviour are functionally related to each other. Consequently, this perspective makes intelligi-ble how the different fields of biology are related, through giving a perspective on how their explananda are related. This integrative