‘It is inconceivable’, Michael Tomasello memorably claimed in a 2010 lecture, ‘that you would ever see two chimpanzees carrying a log together’ (Page-Barbour lecture at the University of Virginia). Decades of research by Tomasello and colleagues – at the Max Planck Institute for Evolutionary Anthropology (of which he is co-director) and elsewhere – have provided extensive data suggesting that whereas human infants and chimps do not differ much at individual problem-solving, when it comes to social and cooperative tasks, humans are without peer. What chimpanzees lack (or have in only rudimentary form) and what humans have in comparative abundance, is what Tomasello calls ‘shared intentionality’. According to the shared intentionality hypothesis, the key development in our ancestors’ cognitive evolution was the ability to form joint goals structured by shared attention and multiple individual sub-goals. This crucial development encouraged new forms of interaction, inference and practical self-guidance, such as monitoring one's own social and communicative behaviour from another's point of view. It makes possible not just mundane tasks like carrying a log together, but is a vital precursor to the astonishingly complex and cumulative human culture that now surrounds us all.
This hypothesis was presented in Tomasello's well-received 2014 book, A Natural History of Human Thinking, as a way of explaining the evolution of human culture, language and social institutions. A Natural History of Human Morality is the companion to this earlier volume, in which Tomasello builds on the previous work to explain how, from this complex cooperative cultural foundation, our ancestors ‘came to engage in moral acts that either subordinated or treated as equal their own interests and the interests of others, even feeling a sense of obligation to do so’ (p. ix). He seeks to account for the emergence of the human sense of fairness, of desert, of mutual respect, of obligations extending to others with whom one has never interacted, and of objective right and wrong. It is a relatively concise book (less than 200 pages) of five chapters, the first being a brief scene-setter. I shall run through the other four chapters before offering some critical comments.
Chapter 2 begins by describing the evolutionary processes that can lead to stable cooperative behaviour – kin selection working at the level of the gene, group selection at the level of a collective, and mutualism and reciprocity at the level of the organism – and discusses the proximate mechanisms that might be expected to subserve these processes. The rest of the chapter paints a picture of the evolutionary starting point to Tomasello's story: the social life of our common ancestor with other great apes approximately 6 million years ago. Tomasello shows admirable restraint in condensing his extensive understanding of chimpanzee and bonobo social cognition down to a few fascinating pages. The picture that emerges is of socially complex creatures whose cooperation is considerable but dominated by competition. When chimps hunt monkeys, for example, ‘what is likely happening is a kind of individualistic coordination . . . The participants are not working together as a “we” in the sense of having a joint goal and individual roles within it’ (pp. 26–7). He also concludes that it is unlikely that chimps have a sense of fairness; in ultimatum games, for example, chimps (unlike humans) will accept any non-zero offer. The chapter, thus, poses a puzzle. Chimps and (by inference) our distant ancestors had little resembling morality governing their social lives, so what processes led to the complex moral thinking in which we are now so well-suited to engage?
Chapter 3 suggests that the catalyst to this revolution was ecological: climate change in Africa prompted our ancestors to move into an open landscape where cooperative hunting became necessary. An important proximate mechanism for regulating increased collaboration was increased sympathy, and to this end Tomasello presents data from developmental psychology showing the extent of sympathy in infant humans. After discussing the emergence of this so-called ‘morality of sympathy’, he turns to the ‘morality of fairness’, which is clearly where the meat of his thesis lies.
The crucial step is the development of a kind of joint agency: individuals who coordinate their respective actions as a means of achieving a shared goal do better (ceteris paribus) if they are able to adopt the perspective of ‘we’: a bird's eye view on collaborative action that encourages a kind of impartiality. Individuals select partners on the basis of their ability to adopt this kind of perspective – for they will make the most fruitful and reliable collaborators – and, knowing this, individuals are motivated to advertise their own cooperativeness. Poor cooperators are provided with incentives to improve via punishment, and occupying the impartial perspective means that if I catch myself being a poor cooperator, I will evaluate myself negatively. If spoils are divided unequally, there will be protests: demand for respect as a contributing collaborator. At this point, thinks Tomasello, a sense of desert emerges. The protest is not just about an unequal distribution of stuff; it is about the unequal distribution of respect. Thus an individual's negative judgement about herself involves the thought that she has not accorded others the respect they deserve, that she has not done what she ought to have done; she feels not just regret (realizing that she will now probably suffer punishment), but experiences guilt. These are not merely precursors to moral judgement; they are the real McCoy.
Chapter 4 picks up the story about 150,000 years ago, when human morality moved from its use in local and temporary contexts to something on an altogether grander scale. Human groups were growing in size, competing with other groups, developing an in-group/out-group mentality. The joint intentionality exhibited by a band of successful hunters, say, scaled up to the collective intentionality of how ‘we’ as a tribe shall act, bringing with it the trappings of loyalty, ethnic markers and norm enforcement by third parties. Tomasello here provides many interesting references to experiments in developmental psychology showing how young children exhibit conformist tendencies, in-group identification and concern with how others will evaluate them.
The norms of the culture were now considered simply as ‘the way things are done’ – the correct behaviours seen as ‘objectively’ right. (Tomasello uses scare quotes on this word consistently, in one instance in a chapter title.) By the time groups of humans left Africa, cultural group selection had become a force shaping the strength and content of moral norms and institutions, favouring the development of laws and organized religion.
In the final chapter Tomasello sketches some alternative approaches to explaining the origin of human morality: so-called evolutionary ethics, moral psychology and cultural evolution. The reader who expects a powerful rebuttal of these views may be disappointed; Tomasello's critique is brief and somewhat diffident.
One of the striking features of this book is the author's sincere effort to connect his evolutionary and empirical approach with contemporary philosophy. There are frequent citations to works by Michael Bratman, Margaret Gilbert, Christine Korsgaard, Thomas Nagel and Shaun Nichols. (Even Hume, Hegel and Nietzsche get a look in.) Where engagement with philosophical thinking is perhaps weaker is an under-appreciation of certain relevant metaethical debates. (Well, being a metaethicist I would think this, wouldn't I?)
It is surprising, for example, that there is never offered a very satisfying characterization of a moral judgement, which is a central concept in the genealogy. Tomasello frequently contrasts the ‘morality of sympathy’ with the ‘morality of fairness’, but it seems reasonable to wonder quite what the former phrase denotes. Cooperation born of sympathy – e.g. helping someone because you love him, because the thought of his suffering upsets you – may be moral in the sense that we sometimes find it praiseworthy (Kant's counterintuitive opinions notwithstanding!), but need involve no moral judgements. The maternal nurturing of many mammals is regulated by something that can reasonably be called ‘sympathy’, but very few mammals (very plausibly none but us) make moral judgements. Where ‘real’ morality lies, I would say, is in what Tomasello calls ‘the morality of fairness’. But of course real morality can concern much more than just issues of fairness. One would, for instance, be hard-pressed to find a disapproval of unfairness underpinning the moral condemnation of incest. Tomasello might respond that moral judgements pertaining to matters having nothing to do with fairness are a case of norms shaped by cultural factors: consider, for example, the kind of moralized disgust that many now feel about smoking cigarettes. But while this is obviously the correct thing to say about many cases, it is less obvious that it generalizes. For example, a moralized aversion to incest (an aversion, that is, that presents as a sense of prohibition, not merely inhibition) may have much more ancient evolutionary roots, and as such would be overlooked by Tomasello's focus on fairness.
Another concept of metaethical interest that Tomasello steers clear of defining is the notion of moral objectivity. As I noted earlier, he opts to flank this term with scare quotes throughout, suggesting a cautiousness that seems sensible but is never explained. Ordinarily scare quotes would indicate an ironic use, or the grudging adoption of someone else's usage from which one wishes to distance oneself. Here, I suspect, the scare quotes are utilized to indicate that his theory aims to explain how humans have come to believe in objective moral truths but doesn't aim to account for the existence of objective moral truths. And this distinction is, of course, of the utmost importance (though I don't think that scare quotes are the best device for capturing it). By analogy, there would be some interest in explaining why humans have a tendency to believe in supernatural beings (in ontogenetic, evolutionary and/or sociological terms), but even an entirely successful explanation on this score would not establish the existence of such beings. Indeed, the person who doesn't believe in such beings might be especially interested in the account of why such beliefs are so prevalent.
What is noteworthy, from a metaethical point of view, about Tomasello's genealogy of human belief in moral objectivity is that it is entirely agreeable to a moral sceptic who maintains that all such beliefs are false. Compare, by contrast, an evolutionary account of why humans are so good at recognizing faces. Here an obvious presupposition of the account would be that there are actually such things as faces: it was adaptive for the human brain to have the ability to recognize and remember faces only because this ability allowed our ancestors to track real ‘face facts’. But it is no part of Tomasello's moral genealogy that it was adaptive for the human brain to have the ability to judge certain actions to be objectively morally right/wrong only because this ability allowed our ancestors to track objective moral facts.
After reading Tomasello's book, then, one might ask the question ‘So is anything objectively morally right or wrong?’ The lurking sceptical worry is that in providing a full account of why humans believe in moral objectivity – an account that appears compatible with there being no such thing – Tomasello actually undermines our justification for holding such beliefs. At one point he very briefly addresses this sceptical worry (p. 7), and shrugs it off as being analogous to declaring that because the evolutionary point of sex is procreation we should never have sex for any other reason, which he correctly rejects as preposterous – of course we may have sex for all sorts of personal reasons. But the analogy doesn't withstand scrutiny. Of the numerous differences between sex and moral judgement, the pertinent one here is that the latter is a species of judgement; and as such it is reasonable to ask questions about moral judgements’ epistemic status (e.g. ‘Are they true?’) in a manner that wouldn't even make sense if asked about the activity of sex. Yes, we are now free to make moral judgements in the service of our own personal goals, but if doubt has arisen as to whether any of them are true (note again: this isn't a doubt that even makes sense regarding sex), then the troubling question that comes into focus is why we should keep making any moral judgements at all. Any answer along the lines of ‘Because it serves our purposes to do so’ confuses instrumental justification with epistemic justification. But in pursuing this I have strayed from evaluating Tomasello's book into mentioning some implications his project may have for metaethics – an area that is not within his intended purview.
The beauty of A Natural History of Human Morality is how smoothly it pulls off several tricky balancing acts. First, it strikes a good balance between brevity and detail. It is evident that Tomasello could, if he wished, discuss these topics at considerable length – and were he to do so it would be no bad thing – but he shows commendable restraint in covering a great deal of ground without ever getting bogged down in details. Second, the author's clear and self-composed writing style makes his view accessible for the non-expert without any hint of ‘dumbing down’: both students and professional academics will find the book engaging. Third, the book strikes the right balance between theorizing at a fairly abstract level and then bringing things down to earth with reference to empirical research. There is a real effort – and a largely successful one – to illuminate the connections between philosophical approaches and experimental results (most especially from developmental and comparative psychology).
The book is both a synthesis and an accessible synopsis of an extensive body of important empirical research and thoughtful theoretical deliberation. Though of course containing conjectures about the distant past of our species, it has a great deal less of a speculative air than most other works in the field. It is, in sum, a major contribution to the contemporary discussion about the origins of human morality, and is a must-read for anyone with an interest in the question.
