Explaining the lack of empathy in supersocial monkeys, part 1
(writing in progress)
Baboons (Papio), drills (Mandrillus) and the gelada Theropithecus), all of which belong to the family Cercopithecidae, are socially the most complex and versatile of all non-human primates. This is revealed in a large body of literature based on many long-term studies (Strum, Kummer, Sapolsky, Altmann, Dunbar, Cheney & Seyfarth, etc.).
Although baboons are not particularly closely related to humans, it is they rather than the great apes which rival humans in social complexity, partly because their groups are larger and more cohesive than those of chimpanzees (Pan). Groups of up to 750? have been recorded ( ), and one species organises its groups according to a five-tier system from family groups through clans and bands to troops and coalesced troops (Kummer ). Mention clear division of genders and presence of inheritance of social rank as well as meritocratic self-advancement of social status.
Despite their social attainments, baboons show less evidence of empathy than either great apes or less gregarious members of the same family, such as the diana monkey (Cercopithecus diana)(ref.). (Perhaps also mention that even some lemurs show signs of empathy.) They also show less empathy than the most intelligent of Neotropical monkeys, particularly capuchins (Cebus), which are not particularly complex socially. This suggests that baboons and their closest relatives have specialised along different lines from the lineage leading via apes to humans, in organising their societies around non-empathetic rather than empathetic principles. If so, what could be the adaptive value of this and which are the pressures of natural selection leading to this surprising specialisation?
We use the term ‘empathy’ to connote a complex syndrome of psychological phenomena with a common theme: morality (see de Waal’s various publications), reciprocal altruism (as opposed to immediate reward), succorative behaviour (as opposed to instinctive care such as maternal behaviour), generosity and donation (as opposed to passive sharing), learning based on teaching (as opposed to passive learning based on trial and error), a sense of humour (as opposed to juvenile play), and a sense of shame (as opposed to mere guilt). Mention ‘theory of mind’ as per the mirror test, which baboons fail but which certain apes pass. ‘Theory of mind’ means a capacity to recognise that another individual has a different viewpoint, which is fundamental to empathy.
What is anomalous about baboons and their closest relatives, and what has never been satisfactorily explained, is the incongruence between their extremely great expression of social intelligence and their extremely small expression of empathy.
Previous authors (e.g. Henzi) have suggested that the social complexity and versatility of baboons have arisen to mitigate intraspecific competition for food (briefly refute this on logical grounds). We propose a new conceptual framework in which the particular immune challenges to baboons and their closest relatives explain a complex syndrome of behaviours and the associated morphological attributes in a consistent way.
The anomaly can be elaborated as follows.
Baboons and their closest relatives are extreme in several aspects of their morphology and behaviour. These aspects have not been satisfactorily explained, but make more sense in the light our new theory of the adaptiveness of a non-empathetic syndrome to the immune challenges faced by a relatively long-lived, slow-breeding mammal.
Behavioural anomalies in baboons relative to social complexity and versatility
Various behaviours of baboons tend to be viewed anthropocentrically, and it has taken intensive studies to correct the false assumptions that began with Eugene Marais (1933?). The following behavioural patterns have provided surprises relative to the social complexity and versatility of baboons.
Minimal reciprocal altruism: Several behaviours of baboons and their closest relatives, particularly grooming, give a superficial impression of empathy. However, …
Minimal teaching. Emphasise that teaching is crucial for technology, and so the lack of teaching in baboons is consistent with the lack of technology in baboons and their closest relatives, which are surprisingly unable even to wield sticks and stones despite their hands being similar to those of humans including the opposability of the pollex.
Minimal begging and sharing of food (mention both cheek pouches and predation of e.g. antelopes and hares)
Minimal sympathy (mention lonely grief)
Minimal courtship (mention that we mean courtship of females by males)
Minimal playing as adults, implying a lack of sense of humour (possibly even in juveniles).
Minimal altruistic defence against predators (despite impressions to the contrary in literature)
Minimal modification of maternal behaviour according to context and circumstance (mention how mother ignores obviously broken limb of infant, or leaves juvenile behind on island in Okavango, Cheney & Seyfarth )
Minimal punishment of males by females for infanticide or hostage-taking
Etc.
A complicating factor is that baboons show great individual variation in behaviour, in some instances apparently including signs of empathy. Notwithstanding this individual variation it is clear from all rigorous studies that baboons differ basically from humans. Empathy is considered normal in human populations, whereas it transpires to be exceptional in populations of baboons.
Morphological features of baboons possibly related to the behavioural anomalies
Baboons and their closest relatives are extremely sexually dimorphic, and the form of the dimorphism is surprising in several ways.
Canine teeth:
The canine teeth of baboons and their closest relatives are remarkable for several reasons besides their great size. Firstly, they are so sexually dimorphic that they are qualitatively different between male and female. Secondly, they are continually honed in two ways by two different teeth on the mandible. Thirdly, …
Oestrus swellings:
Sexual displays on the chest:
Theoretical framework:
It is easy to assume that the evolutionary trend, in primates and mammals generally, towards the social complexity and versatility seen in humans is necessarily and automatically accompanied by the evolution of increased levels of empathy. However, an alternative possibility is that a capacity for empathy represents an evolutionary option, which may not be adaptive in certain niches. Empathy is not necessarily [AM2]a mere corollary of extreme social cognition. The axis of degree of empathy can be viewed as partly independent of other axes, such as degree of social complexity.
According to this conceptual framework, humans combine social complexity with the greatest development of empathy known in any organism. Apes (particularly chimpanzees) are clearly part of the same evolutionary trend as humans but not as advanced in terms of empathy.
However, baboons and their closest relatives appear not to be on the same evolutionary trajectory, because a) their overall brain sizes relative to body sizes are comparable with those of apes, b) they are far more socially complex than any ape and rival humans in this way, and c) they live in different environments from extant apes.
Accordingly, we argue that there have been two different specialisations among the advanced primates. One branch, culminating in baboons, has forged social complexity on a basis in which empathy is at best irrelevant and at worst a hindrance. The other branch, culminating in humans (via apes), has involved a combination of social complexity and empathy.
The basic reason for this dichotomy is the difference in technical capacity. Whereas the lineage via apes to humans is essentially specialised for technological versatility with gregariousness as a corollary, that via minimally gregarious cercopithecids to supergregarious cercopithecids is essentially specialised for ... In humans (and apes) it is ‘what you know’ more than ‘who you know’. In baboons and macaques it is ‘who you know’ more than ‘what you know’.
Our basic argument is that, in order to survive in relatively open and predator-rich environments in semi-terrestrial niches, baboons and macaques rely on ‘strength in numbers’ for vigilance, in much the same way as applies to gregarious ungulates. However, this degree of congregations leads to intraspecific challenges which the cercopithecids have solved – rather counterintuitively from the understandably biased human perspective – by an actual loss of morality AM3.
In other words, baboons and macaques have succeeded on the ground and in the open in extremely hazardous environments by maximising gregariousness at the expense of altruism[AM4]. Humans (via apes), by contrast, have solved the same problem by maximising altruism at the expense of gregariousness. This basic distinction has been inadvertently blurred by a) the extreme gregariousness of modern people (e.g. in cities) and b) the nearly irresistible assumption that, because monkeys resemble humans (and apes) in so many ways, their psychological underpinnings can be assumed to be similar.
Comparisons with other mammals:
Compare baboons and macaques with a) New World monkeys (particularly capuchins), b) canids, c) elephants, and d) dolphins. The point is to show that various mammals, although neither primates nor as socially complex as baboons, show various forms of empathy. For example, canids show extreme generosity towards offspring including those of other individuals within the group. Certain felids teach their offspring in a limited way, e.g. by providing prey to practise on. Elephants have been recorded providing sympathetic support to victims of bullying (see Bekoff), physicaly assist injured individuals to get up, and show signs that they have a concept of death by revisiting the bones of relatives and spending considerable periods touching and smelling these remains. These observations suggest that canids and elephants may possibly possess a ‘theory of mind’, albeit based on olfaction rather than vision. There is also a possibility that dolphins possess a ‘theory of mind’ based on audition.
Explanation of behavioural and morphological specialisations according to non-empathy
Canine teeth: extreme even by the standards of Carnivora, and puzzlingly sexually dimorphic
Oestrus swellings
Cheek pouches
Infantile uniforms
Grooming
Etc.
[AM1]
[AM2]
[AM3]
[AM4]I suggest that a discussion on gregariousness could dilute and/or confuse the points. Perhaps a brief mention of this; but I suggest the main focus is on the theory that morals/compassion are needed for technical species but not non-technical species.
to be continued in ...
(writing in progress)
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