Biological sources of morality: hierarchy and fairness.

We’ve seen before that there is no big mystery surrounding the biological origin of human morality: sociality creates the need for social norms, and thus evolution generated a complex array of natural dispositions that are tuned to allow social interactions and widespread collaboration. I’m not saying that evolutionary psychology has figured it all out, it’s not even close, but the starting point is fairly uncontroversial: social cooperation brings remarkable advantages, but also creates new challenges, namely, the problem of free riders. Morality can be roughly identified as our innate system to cope with the intricate challenges that collaboration generates. More in detail, accepting the selfish gene perspective, one can quickly see that pure and uncompromising collaboration can’t be the solution: as genes compete with one another, those that favoured unbounded collaboration will soon disappear, as the individuals that don’t carry them will exploit gullible collaborators and ripe all benefits.

So far, it’s all orthodox: collaboration allows to multiply (instead of summing) the benefits, but there must be systems to prevent individuals from enjoying the benefits without putting in their fair share of effort. Thus morality arises, giving social mammals feelings such as friendship (a fondness and care for non relatives), empathy, indignation and so on. Another widely accepted view is that this system evolved from the foundation of offspring care. In mammals in particular, caring for the offspring is almost universal (at least among females), and must include what is needed to understand what the little ones need, and the desire to fulfil these needs, so that evolution produced the mechanisms that we now call bonding, empathy and theory of mind. At some level, that’s all that is needed to support already sophisticated sociality: if I can figure out what my children need, feel distressed when they are unhappy and/or when we are separated, just extending all these mechanisms to other individuals will generate fruitful social interactions. Make this extension reciprocal, and you get a tightly bound group that can work as a team.

From here, however, things get messy pretty fast: there is no agreement on what are the fundamental ingredients of our moral inclinations; we know that culture and experience can shape our morality in dramatic ways, and therefore, tracking down a common source is either very difficult or downright impossible. Not a good reason to give up, of course, and in fact, there are lots of people who study moral psychology with an eye for evolutionary explanations. I’ve briefly discussed Paul Bloom‘s latest book: “Just Babies: The Origins of Good and Evil“, if you want to have a good overview of what is being scientifically studied, this book would be my recommendation, it summarises much of the field in a clear and uncontroversial way. I’ve finished my post on “Just Babies” by pointing out that “Bloom and (to my knowledge) most Evolutionary Psychology, largely ignore the effects that leader/subordinate relationships would have had in shaping our moral instincts”, and then took a long pause, also because I was busy reading a complementary book: Patricia Churchland’s “Touching a nerve: The self as brain”. This is another highly recommended book, one that I enjoyed without reservations, probably because its approach is closer to my own: it focuses on brain science, from neurons up, and does so with the eye of a philosopher. Perhaps unsurprisingly, Churchland shows a healthy degree of scepticism towards mainstream evolutionary psychology (I will add my own below), and prefers to focus on down-to-earth neuroscience. The two books therefore are indeed complementary, and approach many similar topics from the two major entry-points that science is pursuing: from bottom up, looking at how neurons and brains generate behaviour or from the top backwards, observing behaviour, finding its psychological foundation, and tentatively proposing evolutionary explanations.

There is a third approach, of course, the purely theoretical one. It uses Evolutionary Game Theory and/or other mathematical models, to explore the conditions that may favour the positive selection of cooperation. Unsurprisingly, I’m strongly attracted by this stream, and I’m very happy to remain in touch with Artem Kaznatcheev and The EGG blog. However, the exciting finding is that all three streams are now cross fertilising each other: both books touch the same topics and cite plenty of similar literature, and eventually mention and find supporting evidence in mathematical models, this is because the three approaches are finally getting in each-other’s sight: I won’t say they are becoming indistinguishable, but they do need to look at, and draw from, each-other’s proceedings.

This long premise was necessary to build my confidence, and put forward a bold claim. There is one key element that is almost missing from all the approaches (but of course, the mathematical side is excused, as modelling what I’ll outline is hardly feasible at the moment): we’ve seen how moral inclinations have probably evolved from parental care, more or less everyone agrees on this, and the parent-offspring relationship is clearly hierarchical, so why is hierarchy confined to the periphery of the discipline? If I’m not mistaken, Bloom spends little or no time exploring the subject, while Patricia gets close, but seems blind to some fairly obvious conjectures. We’ll see below the detail, because in fact, some evolutionary psychology does indeed focus on leadership and hierarchies, but, from my point of view, approaches the topic from the wrong direction. I can’t claim to have a full picture of the field, but as far as I can tell, the main authority in terms of evolutionary theory of leadership is Mark Van Vugt, proposer of, it goes without saying, Evolutionary Leadership Theory (ELT) itself (two citations below, both in open access). ELT is typical Evolutionary Psychology, to the point of being orthodox: sees the mind as modular (where each module has been selected to solve a particular problem), expects our minds to be comprised of modules that were adaptive when and where humans evolved (an ancient savannah), and postulates little or no change since then. It then uses these assumptions to identify problems that can be solved by having a leader (for example, how does a pack decide where to go next?), hypothesises an ideal problem-solving module, and jumps at exploring how such a module can explain the problems of contemporary humans (because, you know, the problems we face today are different!).

Provided that I am all in favour of looking at hierarchy and leadership from an evolutionary perspective, I find this approach limited, over-confident, unjustifiably anthropocentric, and in general, unconvincing. Now, that’s another bold statement, so here are my reasons:

  1. The vast majority of Mammals experience leadership as soon as they are born. Parents look after their offspring; and to do so, they effectively lead the little ones. Parents decide when puppies are allowed to follow and when they should wait hidden in the den (or equivalent), they decide when it’s OK to play, with what, and when. With very little exception, we are all born subordinates (and are frequently surrounded by competing peers, also known as brothers and sisters).
  2. Therefore leadership and subordination have evolved well before the appearance of hominids, and group leadership amongst non-relatives is likely to be an extension of parental care, following the exact tinkering-cum-extension paradigm that justifies the whole field of evolutionary moral psychology.
  3. Hence, if we want to understand what kind of mechanisms exist in present-day humans, the starting point should be a comparative study of different mammals, or if you prefer, good old fashioned ethology. We should be building a phylogeny of behaviours that range from simple parental care, to family leadership, and proceed to larger group hierarchies. Naturally, we can hypothesise that humans are largely unique in organising themselves around groups of non-related individuals, and that such groups usually have one or more leaders, but I would argue that the difference between this kind of arrangement and large multi-generational family groups is very small: both types of groups may follow almost the same rules, there is no obvious a-priori reason why the new kind of group requires a whole set of brand-new rules (with one exception, see below).
  4. Finally, one should be very careful in producing predictions to inform real-world decision making. At best, we would produce a theory, and the real world is likely to have multiple ways to escape the boundaries of any single theory.

Which leads me back to Patricia Churchland. In her book, she discusses our sense of fairness, and correctly observes that we don’t normally follow a “fair for all” paradigm. All human societies show some degree of inequality, between parents and children (surprise!), men and women, teachers and pupils, and so forth. However, we, and at least other primates, do have a sense of fairness, meaning that we dislike it if we are treated worse than our peers (but here I’m already extending what Churchland wrote by introducing the term “peer”). In light of the undeniable variability of inequality across and within different human societies, Churchland concludes:

Thus, when philosophers or psychologists claim that we humans are all born with an innate module to behave according to fairness norms, we should wonder how they square such a hypothesis with the aforementioned variability. (p.114)

She is right, of course. Such variability has to be explained, and a simple “fair is good” predisposition does not cut it. However, if we shift the centre of the picture from fairness to hierarchy, suddenly it all becomes simpler. We are born expecting to be led, and since we also must have the appropriate machinery to raise our own offspring, we also have what is required to lead (with exceptions, of course). Thus, we must be innately able to recognise the roles of leader and follower. This can be directly generalised into a fully formed hierarchy, or the famous “pecking order”, and a sense of fairness would be expected to reflect it. In other words, the “prediction” would be that we consider fair an equitable treatment amongst our peers, but that we do expect our leader to precede us in the pecking order, and symmetrically, we require our subordinates to wait for their turn (e.g. we have a sense of inequitable fairness!).

So yes, we may indeed have a “fairness” module (on first approximation!) but this would be part of a “hierarchy” system, it is not reasonable to expect it to work in isolation.

Before concluding, I’ll mention how the “parental origin” of our hierarchical structures is supported by obvious evidence, and allows to neatly interpret what happens in real world groups. First of all, domestication. It is well known that domesticated breeds show various degrees of neoteny (the retention, in adult age, of juvenile traits), see for example the story of the Russian domesticated Foxes, or Coppinger 1987 (citation is below) if you want an academic perspective. This confirms that parental care is evolutionarily linked to our predisposition to organise ourselves in hierarchical structures.

Second, one would predict that we expect to be treated equitably when compared to who we consider our peers, but won’t be equally offended if someone who we consider our superior gets, for example, a higher pay. Finally, we would expect us to have strong adverse reactions if our acknowledged superiors show not to care for his subjects, or worse, if those below us don’t care for our own well-being. This is what causes “righteous indignation” (and I know first-hand that it is a powerful emotion), if we assume that non-parental hierarchies are an extension of the pre-existing mechanism, it follows that one change is strictly necessary. In the case of parenthood, it is in the selfish interest of the parent’s genes to care for the offspring, as such, it can be taken largely for granted (the genes that don’t allow this care will disappear pretty fast) from the perspective of the youngsters. This isn’t the case for larger groups: the leader will always be in the position of exploiting the pack and give too little in exchange, therefore a powerful system needs to be in-place, in order to make sure that exploitation amongst non-peers doesn’t neutralise the benefits of collaboration. It’s the free-rider problem as it happens in the real world: I certainly have never heard of packs of collaborating animals that do not have a leader or a pecking order. I’m sure they exist, but they would be the exception, making the “free-rider amongst peers” a special case of the typical situation (my boss is a je*k).

Take home messages:

  • Good evolutionary psychology needs to avoid anthropocentrism: most of what makes us human pre-dates us by a long shot, and this includes behaviour, cognition and hence psychology (including moral psychology).
  • Hierarchy and leadership are fundamental to understand human morality. Our sense of what is fair and our ability of getting “righteously indignant” are shaped by the long history of parental care, and collaboration within hierarchical groups (and all pet-owners know that cats and dogs have the same ability, neotenic or not!).
  • The “free rider” problem, that occupies the thoughts of many evolutionary scientists, is somewhat overestimated. When the aim is to study collaboration, hierarchy and leadership generate a whole lot of somewhat different problems that precede and pre-date those that arise in peer to peer interactions.



Bloom, P. (2013). Just Babies: The Origins of Good and Evil. Random House LLC. ISBN: 978-1847921628

Churchland, P. S. (2013). Touching a nerve: The self as brain. WW Norton & Company.

Coppinger R., Glendinning J., Torop E., Matthay C., Sutherland M. & Smith C. (1987). Degree of Behavioral Neoteny Differentiates Canid Polymorphs, Ethology, 75 (2) 89-108. DOI:

Fowler J.H. (2005). Human cooperation: Second-order free-riding problem solved?, Nature, 437 (7058) E8-E8. DOI:

Van Vugt M. (2006). Evolutionary Origins of Leadership and Followership, Personality and Social Psychology Review, 10 (4) 354-371. DOI:

Vugt M.V. & Ronay R. (2014). The evolutionary psychology of leadership: Theory, review, and roadmap, Organizational Psychology Review, 4 (1) 74-95. DOI:

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Posted in Ethics, Evolution, Evolutionary Psychology, Science
2 comments on “Biological sources of morality: hierarchy and fairness.
  1. […] written before about righteous indignation, but haven’t even touched its most peculiar property: asymmetry. Ever wondered why people […]

  2. […] solid EP; I will also raise a couple of points on the evolution of Righteous Indignation (see my previous post on this, with examples of EP theories that I do not like too much). To be precise, I will comment […]

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