It is hard to explain how human morality has evolved. Explanations regarding evolutionary self-interest seem to explain away the phenomenon, rather than illuminating it. But without showing how behaving morally helped our ancestors to have more or better offspring, a strictly evolutionary explanation will not succeed. Typically, those that try to illuminate the evolutionary origins of morality focus on either reciprocal altruism (roughly, I lose now, but I’ll gain later) or inclusive fitness (roughly, I seem to lose but some of my kin gains, so I gain), but both approaches face difficult problems. Michael Tomasello, Co-director of the Max-Planck Institute for Evolutionary Anthropology in Leipzig, takes a different route. In his exciting new book, he puts forward a strong case for mutualism, the thesis that moral behaviour evolved as the result of mutually beneficial interactions amongst humans.

Tomasello’s core thesis is that mutualistic cooperation, in which all involved parties benefit, provided the ground for the evolution of proximate psychological mechanisms that eventually formed the building blocks of human morality. He identifies two ecological changes that made humans interdependent and explains how these conditions gave rise to the evolution of, first, joint and later collective intentionality. Tomasello’s account is superbly researched and convincingly argued. Its foremost contribution is to broaden the conception of reciprocity through insight from psychological research that yields an account of how the socio-ecological circumstances of early humans made could have made cooperation worthwhile in an evolutionary sense.

Tomasello develops his thesis in five chapters. Chapter 1 introduces the interdependence hypothesis and the distinction between the morality of sympathy and themorality of fairness. The former concerns behaviour motivated by feelings of sympathy. Tomasello finds much evidence for it in great apes already. The morality of fairness, however, is unique in human beings and concerns principled behaviour that is not strategic, self-interested or primarily motived by sympathy (others, for example primatologist Frans de Waal, think that the morality of fairness is present in apes, too). Much of the book is concerned with explaining the evolution of the latter.

Chapter 2 compares research on great apes (mostly chimpanzees) and human children. Great apes are capable of impressive feats of (strategic) cooperation and they seem to have ‘friends’ amongst each other for which they harbour feelings of sympathy. However, compared with the benchmark behaviour of human children, our nearest living relatives fare poorly. Citing numerous studies, Tomasello shows how human children are born ‘collaboration machines’ with a genuine sense of fairness. Great apes, however, lack the latter and when push comes to shove, then dominance rules the ape’s day (33).  

Taking a cue from philosopher David Hume, Tomasello identifies the absence of both dominance structures and independence as the conditions that “propelled the human species from strategic cooperation to genuine morality” (4). The two steps of Tomasello’s evolutionary narrative, the development of joint intentionality and collective intentionality, are spelt out in chapters 3 and 4, respectively. Each chapter follows a similar plot. Tomasello identifies ecological conditions that had an impact on human beings, illustrates how human behaviour changed as a consequence, and finally describes how proximate, psychological mechanisms resulted that eventually led to human morality. The first crucial event, about 400,000 years ago, was the scarcity of individually attainable resources and the resulting interdependence of early humans in their foraging efforts, most vividly expressed in the hunting of big game (44). Humans had to collaborate with one another or else die (136). This setting explains the evolution of joint intentionality.Early humans learned to perceive each as equals in their joint activities (55). Role ideals and norms about proper behaviour in joint activities developed. Human psychology was moulded so that it could function adaptively in this new environment – sympathy and care were important proximate mechanisms (129). Joint commitments to collaborate created an “external arbiter” that sanctioned behaviour that failed to live up to the role ideals. In a second step, Tomasello argues that such norms and role-ideals extended to all members of society after a second crucial socio-ecological change, which was the population increase and inter-group competition that began around 150,000 years ago. This setting explains the evolution of collective intentionality. To survive, modern humans depended on their groups. Being an efficient member of the group at all times was thus essential. Crucially, modern humans did not create the norms that governed their society, but they were born into them and thus accepted them as an objective reality that applied equally to all members of their group (123). 

In chapter 5 Tomasello revisits the crucial aspects of his argument, provides a concise summary, and evaluates his theory compared to existing accounts in the literature.

Tomasello’s nuanced and wide-ranging argument deserves much discussion. Let me highlight just two points. First, empirical research on morality is all too often problematic (at least in the eyes of some philosophers) as it might simplify or neglect crucial aspects of the phenomenon in an attempt to study it empirically. What might be explained, in these cases, is how sympathy came about, or reciprocal behaviour, or obedience to authority, but not morality.

Tomasello does not make this mistake. He is acutely aware of the history of moral philosophy and often references current philosophical theorising on morality. On Tomasello’s account, the first evolutionary step towards morality is the ability to be guided by reasons that are neither your own nor those of your collaborative partner, but joint reasons that spring from your collaborative relationship. This idea of a ‘second-personal’ standpoint as a core tenet of morality is inspired by philosopher Stephen Darwall (2009). The latter, however, understands the second personal standpoint as providing normative reasons for anyone. In contrast, Tomasello construes it psychologically, and limited to those that are presently involved in a particular joint activity. In his second explanatory step, Tomasello focuses what might be called the objective-seeming features of morality (which he is careful always to bracket as ‘objectivity’). He uses philosopher Thomas Nagel’s demanding view of moral objectivity to construe his explanandum. Binding rules for all members of society, which depends on viewing oneself as equal to one’s peers as if seen from a ‘view from nowhere’ that detaches itself from personal interests and contingencies (1986). Both of Tomasello’s philosophical commitments might be questioned, although metaphysical or epistemological qualms are not at issue here. They are valid operationalisations in the limited sense that Tomasello subscribes to them. His attempt to explain such an ‘objective’ feature of morality should be seen as a kind of ‘stress-test’ for his theory. If he successfully explains the evolution of ‘objective’ morality in Nagel’s and Darwall’s sense, then explaining morality understood as a subjective or relativistic system of rules will likely succeed, too.

I have some doubts about Tomasello’s case for the interdependence of modern humans. Modern humans, from about 150,000 years ago, “began forming separate and distinct cultural groups that competed with one another for resources”, which Tomasello also dubs a “collaborative enterprise” in which all “members needed to do well so that [the group] could do well” (85). Interdependence in the modern human case is more complex than interdependence in the case of collaborative foraging. For example, the outcome of a hunting party of two depends on both hunters in a direct and immediate sense. In contrast, the ‘outcome’ of cultural groups is only indirectly, if at all, traceable to individual members within the group. This makes it more difficult to argue that modern human were likely to perceive themselves to be interdependent, which makes it more difficult to see why they developed psychological dispositions to view all members of their group as equals. Tomasello’s model of modern human interdependence requires two things. First, the roles within a cultural group must be of equal importance to the outcome of the group. Tomasello suggests that the ‘outcome’ of a group is measured by its ability to compete with other groups. It seems likely that some members of the group contributed a lot to this endeavour, physically strong males, for example, while others contributed less. Tomasello also mentions the “smooth functioning” of groups; thus, there might other ways, not directly related to competing with other groups, by which members of the group may contribute (122). The ability to make stone tools, the ability to assuage internal conflicts, or the ability to skin an animal might have been important factors. But it is an open question whether these roles, the warrior, the mason, the appeaser, and the skinner, were also perceived to contribute equally to the group’s outcome. Several hunter-gatherer societies that are studied today, for example the Inuit, seem to distinguish amongst members that contribute to the group and those that don’t. Old and immobile people, for example, may become a burden for their group and may thus forfeit the right to live. Similarly, the ability required to fulfil certain roles might have varied and those that required rarer skill might have been perceived to be of greater value. While there might have been person-independent roles, and thus equality at this level, a hierarchy of roles within a group seems likely, too. It is thus harder to be convinced by Tomasello’s case for interdependence amongst collaborative foragers than in the case of modern human cultural groups.

All in all, Tomasello’s book makes a strong case for the mutualistic approach to explaining the evolution of morality. At times it is quite dense, presupposes some knowledge of technical terms, and will thus be a challenge for the non-specialist. Nonetheless, it is all the more rewarding. Few have considered the evolution of morality in such great detail as Tomasello. And fewer yet have managed to communicate so much anthropological and psychological insight, empirical research, and theoretical synthesis with such precision and eloquence. Tomasello’s book strikes me as one of the best comprehensive, empirically supported accounts of the evolution of morality in print.

I recommend this book to all who are interested in morality – it pans out the mutualistic perspective in great detail and offers a compelling argument for why moral behaviour was (and, I believe, still is) good for all of us.

 

References

Darwall, Stephen L. (2006): The second-person standpoint. Morality, respect, and accountability. Cambridge, Mass.: Harvard University Press.

Nagel, Thomas (1986): The view from nowhere. New York: Oxford University Press.

 

© 2016 Michael Klenk

 

Michael Klenk, Ph.D. Candidate in Philosophy, Utrecht University, The Netherlands.