[Image] I've previously argued that when a human group exceeds the Dunbar Number, 150, that it can no longer adequately keep track of compliance with social norms. Dunbar discovered a ratio between the size of the neocortex of the brain of mammals and the size of group they can sustain. The idea being that social animals need to know about the status and relationships of other members of their group in order to successfully navigate the social sphere. In primates one of the main ways of maintaining relationships was one-to-one grooming. However Dunbar notes that as human groups got bigger along with a bigger neocortex, there was simply not enough time for grooming with everyone. So less direct ways of achieving group cohesion developed. Dunbar has suggested for example that group singing and dancing, both known to stimulate endorphin production, helped to produce a communal sense of well being. (see Dunbar 2014)
Probably at least from the time of anatomically modern humans (ca 200,000 years before the present) our communities were seen from within as being surrounded by a halo of supernatural beings. Our own ancestors would have been chief amongst them, but this halo also contained animistic spirits of place, trees and other significant objects. Evolutionary psychologists, such as Justin L. Barrett, Stewart Guthrie, and Ara Norenzayan, have described how our minds have evolved to find supernatural entities plausible. Once these functions of our minds were in place, the emergence of the supernatural was more or less a given. Most humans, at most times and in most places believe in supernatural agents. It's a side effect of how human minds in general work. I explored why this might be so in my two part essay on why karma and rebirth seem plausible. 
Western
Educated
Industrialised
Rich
Democratic In fact, not believing in the supernatural is a feature of WEIRDness, where the acronym stands for Western, Educated, Industrialised, Rich, and Democratic. Norenzayan has shown that people from WEIRD nations are psychological outliers: "WEIRD people occupy the extreme end of [the spectrum of human psychology]... WEIRD populations are atypical of other human populations" (52-53). There suggests that there is something about being WEIRD that alters the way we process sensory information and makes the supernatural seem less plausible. But we're not quite sure what that something is yet. And being WEIRD does not guarantee that people find the supernatural implausible, because many of us WEIRDos still do find it plausible. It simply makes it more likely. 
Living in groups is a highly successful strategy for survival and evolutionary fitness. Collectively we are much stronger and smarter. In small human groups, it is very easy for each member to monitor the behaviour of the others to ensure there are no freeloaders or backsliders. We know when members are following group norms and when they are not; we know when people are pulling their weight or slacking. Thus surveillance and compliance emerges from day to day interactions rather than being a special function. Members of the group conform because they know that everyone else sees what they do. And that conformity is part of what makes a social species successful. The possibility of deliberate deception in fact only seems to arise in the primates. 
For a society below the Dunbar threshold, bad behaviour might not always be seen to arise out of individual evil intention. There is always the possibility that an individual has been affected by a mischievous or malign spirit, or by magic. Breaking norms does not always call for punishment. Indeed punishment is a poor way to try to re-establish broken trust. Punishment relies on fear to enforce norms. Trust can't be based on fear. Repairing the breach might mean identifying an environmental or a supernatural cause. This has real advantages in a small community. The individual is not victimised by the group, but reminded on their absolute reliance on the group, and is left with their connections to the group intact. The small, isolated group needs each individual as much as the individual needs the group. The problem can be resolved without polarising the group against the individual and vice versa. A common enemy brings people together.
So a breach of norms can be an opportunity to examine how well integrated the wrong-doer is into the community, or to look for environmental problems (whether natural or supernatural). This might not play out in a way that a WEIRDo can recognise. Sometimes the actions of such communities can seem to lack logic from the outside. WEIRDos may label this as "irrational" and so on. Ariel Glucklich's observations about how Tantric magic functions in modern day Varanasi showed that apparently irrational actions have their own internal logic. They can be part of a worldview in which interconnectedness is the highest value: Magic is based on a unique type of consciousness: the awareness of the interrelatedness of all things in the world by means of simple but refined sense perception... magical actions... constitute a direct, ritual way of restoring the experience of relatedness in cases where that experience has been broken by disease, drought, war, or any number of other events. (1997: 12) Interrelatedness is what makes a social group function. Awareness of this, awareness of the relations in the group are crucial to a well functioning group. A group member who does something selfish is not necessarily seen as wicked. They might simply be unintegrated for some reason, probably beyond their control.

Growing Larger

When the human group size crosses the Dunbar number threshold this mechanism for maintaining the group can fail. It becomes possible for members to break the norms of behaviour, to deceive the group, to freeload, for example, and for no one to notice. This is a massive problem for a group which depends, at many levels, for it's survival on everyone doing their bit. Surveillance needs to become a special function. And how does this happen when actions can be performed in private? What Norenzayan and others have argued is that supernatural agents stepped in (so to speak).
My version of this process is to imagine a group of humans living together with their halo of ancestors and nature spirits. Some effort goes into living well with the supernatural members of the community - offerings are made, ceremonies conducted and so on. Specialists emerge who are adept at communicating with the spirits. We can call these adepts shaman. The shaman serves as intermediary between the communities in the different worlds. They interpret the will of the spirits for the humans, and also can call on spirits for help. The shaman also understands how to reintegrate group members who have become disconnected. "Healing" may well simply consist of helping someone experience the fullness of their interconnectedness.
One thing about spirits is that they are already counter-intuitive. They are living things with no physical presence, no breath, and yet they interact with the physical world, which is counter-intuitive even for pre-modern groups. In this case, it is not a stretch to attribute to them other counter-intuitive abilities, such as the ability to observe actions carried out in private. Indeed in a world where invisible agents are normal, one never knows when one of them is looking over one's shoulder. So a supernatural watcher who does not have the physical limitations of a human body, can be anywhere and see anything.

So to some extent the larger groups rely on supernatural monitors. This works if people believe they are being monitored. Norenzayan recounts several experiments that seem to confirm that people who understand themselves to be observed behave better than those who think they are not observed. For a supernatural monitor the effect is only seen in believers. So groups that have supernatural monitors will be more successful because they are more coherent. Narenzayan's major thesis is that religion, with its emphasis on supernatural monitors enabled much larger groups and facilitated cooperation on a much larger scale that might otherwise have been the case. 
As with any community some members stand out. Over time certain spirits took on greater roles. Presumably certain spirits took on the role of supervisor or what Norenzayan calls a "supernatural monitor". And perhaps the supervisor was also involved in helping to mend breaches of trust and keeping people integrated. But as groups got even larger, into the range of thousands of people, the whole system became less and less personal. While we can certainly be on nodding terms with a much larger group of people, we cannot have intimate knowledge of them. In small hunter-gatherer situations strangers are rare and maybe poorly tolerated. Strangers may indeed simply be killed on sight. In a tribe of 1500 members, strangers within the group start to become routine. When there are a number of tribes in an area, out-group strangers would also be relatively common. Tolerance of strangers is required for trade. Groups would have to have developed ways of recognising strangers as part of the same group. This would involve external signs of membership such as clothing, distinctive ornaments or body modifications. And there is simply no way to feel part of such a large group in the same way that one feels part of one's immediate group. Obeying the norms of a group of 1500 is a different proposition to obeying the norms of a group of 150. On the family or clan level the approach of integration continued to function. But on the tribal level they simply could not and so an individual compliance at this larger level came down to rewards and punishments.
The supernatural agents who were now doing the surveillance, aided by those who interpreted the spirit world, became increasingly important to these larger societies. As we have noted, people are far more likely to follow group norms (to "behave themselves") if they think they are being observed. Invisible agents are always on the case. Always watching. Indeed the ability of the supernatural monitors was stretched until they saw everything. One of the main features of the "Big Gods", which Norenzayan describes, is their omniscience. They see everything and thus help to ensure compliance because members of groups with such surveillance always have the sense that they are being observed. Thus local spirits evolved into Big Gods. And Big Gods helped to ensure the coherence and success of larger and larger groups of people who had less and less in common.


Karma as Monitor
In the Ṛgveda we see two gods that are concerned with monitoring: Mitra and Varuṇa. However, these two gods fade from view. Around the time of the second urbanisation the story of supernatural monitoring takes an unusual turn. Animistic spirits are typically either animal or human in form, or sometimes a hybrid of the two.  And Indian myth certainly has plenty of these. Karma, the supernatural monitor of Upaniṣdic Brahmins, Buddhists and Jains, was neither. Karma was conceived of as a "force of nature", abstract and formless. To the best of my knowledge this change has not received any attention from scholars. Diachronic or longitudinal studies of religion over time in India seem not to be very popular. Most scholarship, even comparative studies, is synchronic or focussed on a particular time.

Different versions of karma emerged in different communities, and especially in Buddhism, within communities, but karma never takes form, never stops being abstract. Karma is always an invisible link between action and consequence. Later it is likened to the process which links a seed to a flower (bījaniyama) and to the timeliness of other natural processes (utuniyama), but such similes only tell us that Buddhists saw karma as another natural process that they did no understand. This form of supernatural monitoring has received only scant attention so far from evolutionary psychologists who all seem to be obsessed with gods. One can understand this bias to some extent, most evolutionary psychology work is being carried out by WEIRDos, some of it by theists (Barrett), and a lot of it in an atmosphere of bitter rivalry between atheists and theists (especially in the USA). Still the Indian situation must surely shed important light on the evolution process precisely because karma as supernatural monitor is not anthropomorphised.

What I wanted to highlight in this essay is that, despite the fact that karma is a force of nature and not a being, in some cases the Buddha gains access to the god-like viewpoint of a supernatural monitor. And initially at least, he does so without becoming a god or an intercessory saviour. In some accounts of the Buddha's awakening he attains the three kinds of knowledge (tevijja): the knowledge that comes from recollection of former lives (pubbenivāsānussatiñāṇa); knowledge of the death and rebirth of beings [according to their karma] (sattānaṃ cutūpapātañāṇa); and knowledge of the destruction of the āsavas (āsavānaṃ khayañāṇa). It is particularly the first and second of the vijjās that concern us here. In a worldview with a cyclic eschatology, any supernatural monitor is going to be concerned with ensuring that people get the rebirth they have earned. Karma is primarily a way of explaining how rebirth works to fulfil the Buddhist version of a just world. Wicked people go to bad destinations (duggati) where the predominant experience is misery; while good people go to a good destination (sugati) where the predominant experience is happiness. 
But Buddhism is also a hybrid system (according to my own taxonomy of afterlife types) because the really exemplary people are not reborn at all. This is necessary because even in the best of all possible rebirths—to the Brahmā realm—one lives a long, blissful life, but one still dies. And there is no greater misery than death. Thus the ultimate aim of traditionalist Buddhism is to avoid rebirth altogether, with some adding the caveat that they wish to go last amongst all beings and will help others to end rebirth first. For Brahmins, escaping from rebirth means this involves merging with Brahman, as the wave merges back into the ocean having arisen, crested and broken. Buddhists, by contrast, were cagey about the afterlife of one who was "in that state" (tathā-gata) of not being reborn. Any kind of permanence would wreak havoc on Buddhist metaphysics.
So the Buddha gains access to the god-like knowledge of a universal supernatural monitor. He gains knowledge not only of his own previous lives (pubbenivāsa), but of the death and rebirth (cuta-upapāta) of other beings. Such knowledge requires that one be aware of everything that is happening everywhere at all times, i.e. omnipresence and omniscience. These two qualities specifically denied the Buddha by the early Buddhist texts (see Kalupahana 1992: 43-4). However as time goes on the Buddha becomes more and more god-like. His limitations are gradually weeded out and his abilities expanded. For later Buddhists the Buddha is omnipresent and omniscient, and they gradually add omnipotence to the list as well. I discussed this trend in my 2014 article on karma in the Journal of Buddhist Ethics.

An almost exact translation of omni-scient in Sanskrit is sarva-jñā. This, along with it's synonym prajñāparamitā 'perfection of understanding', are both qualities attributed to the Buddha in Mahāyāna texts. And yet despite all of this, karma remains the primary way of thinking about morality. Of course karma changes with time, as I describe in my 2014 article, and while such changes undermine the role of the karma as supernatural monitor and claw back some of the power into human hands, especially in the matter of avoiding the consequences of evil actions, it is still karma that governs rebirth.
Just as the bodhisatva approaches Buddhahood (the end of rebirth) but continues to be reborn in order to stay in play with living beings; the Buddha seems to approach godhood but never quite cross the threshold. So when Amitābha promises the believer that they will be met after death and guided to a place where the Dharma is almost infinitely easy to practice, he still cannot avoid the need for individuals to awaken themselves. In Sukhāvati everything one needs to practice the Dharma is laid on in abundance, there's no sex or other possible distractions, and yet one must still learn and practice. Awakening cannot be bestowed like grace. Even in tantra, in the ritual recapitulation of Mahāvairocana's communication of awakening to Vajrasatva through mudra, mantra, and maṇḍala, it is not a matter of a deity transforming the sādhaka, it is a matter of the individual and cosmic wills coming together to transform each other. A relationship of give and take or kaji as the Japanese call adhiṣṭhāna. 

Conclusion

A full account of karma in evolutionary terms seems a long way off simply because it does not seem to interest either the Evolutionary or the Buddhist research communities. Evolutionary study of religion is focussed on theism since this is the major issue for WEIRDos. In any case it would be a complex undertaking because karma is complex at any given time, across sects, and changes considerably over time. A complete chronological account of karma would be a good first step towards a complete picture. But for some reason such fundamental research has, to the best of my knowledge, yet to be undertaken. Of course there are many partial studies of karma in specific circumstance, and very many which seek to understand karma in modernist terms, but there is nothing like, say, the major studies of dharma theory (e.g. Ronkin 2005) or the khandhas (Hamilton 2000). I've attempted to trace one major change in karma in my 2014 article and other facets of karma in essays here on my blog, but there are no major studies of karma as far as I know.
One of the problems we face with Buddhist studies is that cracks get plastered over. Even academics seem to aim at producing normative accounts of Buddhist doctrines, to get at the putative underlying unity of the texts, rather critiquing the ideas in Buddhist accounts. There is no tradition of critiquing Buddhism, except in theist terms. Worse, I now see the idea of underlying unity as a myth rather than a reality. Taking that myth too literally is a major impediment to understanding the development of Buddhism. The doctrine of karma is one of the weaknesses, because it fundamentally contradicts and is contracted by the doctrine of dependent arising. Here is another potential crack: how does one gain a godlike perspective, omniscient and omnipresent, on a process like karma? Given how karma works, how is any such perspective possible? The idea is deeply self-contradictory.

That said, this fact that the Buddha gains access to the god-like perspective of a supernatural monitor is a fascinating facet of Indian and Buddhist metaphysics. It tells us that despite the abstract conception of karma, that a godlike perspective is still possible. Buddhists believed (and in some cases still believe) that there is a view point in the universe which sees everything and knows everything and it is in theory possible to attain this view point. This perspective, initially at least, conveys knowledge, but not the power to change the situation. For early Buddhists, changing the situation could only come from practising the practices. Though of course the Buddha's personal power increases. In the later version of the Samaññaphala Sutta simply meeting the Buddha and hearing a Dharma talk rescues the murderous King Ajātasattu from his fate of rebirth in Hell. This whole change in the dynamic of karma in a world of the increasing soteriological power of the Buddha requires further study.

As Buddhism continues to be assimilated into WEIRD cultures it will inevitably change. History shows that Buddhism adapts to suit the needs of the time and place that Buddhists live in. In WEIRD places our problems are distinct from those of Iron Age or Medieval India or Asia. Supernatural explanations seem less plausible and satisfying to an increasing number of people who are none-the-less attracted to Buddhism, precisely because Buddhists promote Buddhism with realist rhetoric (we can teach you about the nature of reality). Redefining Buddhism without the supernatural elements is an ongoing process. Letting go of the accretions that make us think we understand "reality" may take even longer. I think we are generations away from a workable demystified Buddhism that can stand alone without constant reference to tradition. I think that evolutionary theory will play a major role in creating this new form of Buddhism. It is by far the most important single idea to emerge from WEIRD culture in terms of how we understand ourselves. 
~~oOo~~

Bibliography

Attwood, Jayarava. (2014) Escaping the Inescapable: Changes in Buddhist Karma. Journal of Buddhist Ethics 21: 503-535.
Barrett, Justin L. (2004) Why Would Anyone Believe in God? Altamira Press.
Dunbar, Robin. (2014) Human Evolution: A Pelican Introduction. Pelican.
Glucklich, Ariel. (1997) The End of Magic. New York, Oxford University Press.
Guthrie, S. (1993). Faces in the clouds. New York: Oxford University Press.
Hamilton, Sue. (2000) Early Buddhism: A New Approach. London: Routledge.
Norenzayan, Ara. (2013) Big Gods: How Religion Transformed Cooperation and Conflict. Princeton University Press.
Ronkin, Noa. (2005) Early Buddhist Metaphysics. Routledge.


Note. A few minutes after clicking the "publish" button on this essay I noted another blog: Subliminal religious prompts might not make people nicer after all, which contradicts the findings that Norenzayan relies heavily on in his account of religion.