Did your brain evolve in order to understand God?

Feb 15, 2006 Alun Politics, Science 5 Comments Evolution, Evolutionary Psychology, Religion, Robin Dunbar

A couple of weeks back there was an intriguing art­icle in New Sci­ent­ist on how reli­gion came to be by the Evol­u­tion­ary Psy­cho­lo­gist Robin Dun­bar. He star­ted from the assump­tion that ori­gin­ally reli­gion didn’t exist, so some­time in our past it came to be inven­ted. His argu­ment is that reli­gion requires a com­plic­ated brain to make sense, so it was a rel­at­ively recent inven­tion. It’s all to do with orders of intentionality.

Anim­als don’t have reli­gion because they only have first order inten­tion­al­ity. They think purely from their own pos­i­tion. An excep­tion are some great apes. Chim­pan­zees for example can deceive. They can pre­tend not to notice some­thing they want, and so not draw other chimps’ atten­tion to it, return­ing to retrieve the item when the area is quieter. If I think to leave the banana to you won’t know about it, that’s second order inten­tion­al­ity. It means that chim­pan­zees have a the­ory of mind and have more social beha­viours than your aver­age animal.

Things get more inter­est­ing when you have three orders of inten­tion­al­ity. The example Dun­bar uses is “I believe God wants me to act in a right­eous man­ner.” I think that God thinks I should think about what I’m doing. Three steps and you have a capa­city for per­sonal religion.

Dun­bar adds in your mind to cre­ate fourth order inten­tion­al­ity. In his words “I want you to believe that God wants us to act right­eously.” This makes what he calls social reli­gion pos­sible. But he says that still doesn’t com­mit you any­thing, so a fifth order “I want you to know that we both believe that God wants us to act right­eously,” is neces­sary for com­munal religion.

I think that con­firms my sub-human status as I’m still hav­ing trouble fol­low­ing that. If I decon­struct that cor­rectly then fourth-order inten­tion­al­ity is I know that you know that God knows what I’m think­ing. That’s four steps and I’m happy with that. The fifth-order is I know that you know that we know that God knows what I’m think­ing. Dun­bar argues else­where that Shakespeare was doing well because he wrote in the fifth order and because that was his inten­tion he must have been oper­at­ing at sixth-order [Word Doc / HTML]. But that’s rare.

The effort in reach­ing these higher levels is dif­fi­cult. The Social Brain Hypo­thesis [PDF / HTML] is that the brain had to develop the com­plex­ity to manip­u­late inform­a­tion in a social arms race. Except with more brains and fewer arms. This has advant­ages for the indi­vidual, but soph­ist­ic­ated thinkers also have an advant­age as a group. Group inten­tion­al­ity as ordered by reli­gion becomes pos­sible and this may have been an advant­age that archaic Homo Sapi­ens had over its con­tem­por­ar­ies. He’s even got nice graphs to show it.

Graphs show­ing orders of inten­tion­al­ity in prim­ates from New Scientist.

The graph on the left shows a lin­ear cor­rel­a­tion between the size of a primate’s frontal lobes in the brain and their achiev­able order of inten­tion­al­ity. The graph on the right shows (lets ignore Neander­thals for now) how increas­ing orders of inten­tion­al­ity came through evol­u­tion. Aus­tralo­pithecines, like apes, had second-order thought while Homo Erectus had third-order. It looks neat and I’m not con­vinced. Nearly every data point is inter­pol­ated rather than meas­ured. The order of inten­tion­al­ity is dir­ectly pro­por­tional to meas­ure­ments of cra­nial capa­city. If the cor­rel­a­tion is proven then that’s sound, but all we have are the three data points on the left graph to sup­port this. What the right graph really tells us is that cra­nial capa­city has ten­ded to increase in spe­cies of Homo over time and that’s not huge news. It’s also a prob­lem when we do think about Neanderthals.

Neander­thal brains were on aver­age around 10% big­ger than mod­ern humans. That would place them slightly above us on the graph and the sheer spread of Neander­thal points com­pared to the one for mod­ern humans is a bit mis­lead­ing. It would sug­gest that Neander­thals were cap­able of deeper think­ing than us, and that’s a dif­fi­culty because we don’t know if – or to what degree – Neander­thals were cap­able of sym­bolic thought. I have a sus­pi­cion that, like mod­ern humans, they were cap­able of sym­bolic but like con­tem­por­ary Homo sapi­ens they didn’t have much sym­bolic thought. A lot of sym­bol­ism, like cave paint­ings or fig­ur­ines, doesn’t date till after the Neander­thals are gone. It could be that Neander­thals were vic­tims of a Great Leap For­ward in archaic humans, but it’s not cer­tain. How­ever much I’m will­ing to credit to Neander­thals, I couldn’t ser­i­ously argue they were more soph­ist­ic­ated thinkers than Homo sapi­ens. The flints found at sites are also an indic­ator of a degree of brain power and while they were good, they weren’t Homo sapi­ens. So I’m far from con­vinced that the lin­ear cor­rel­a­tion holds for Neander­thals and, if that’s the case, why should it also hold for other hom­in­ids? This objec­tion has implic­a­tions for the tim­ing of how com­plex thought arose, but I don’t think it under­mines his cent­ral thesis, that reli­gion is a res­ult of increas­ing com­plex­ity in the mind brought on to deal with soci­etal stresses.

It’s an explan­a­tion that has spooky poetic qual­it­ies if you want to get mys­tical. The idea of being given a land to con­quer by the will of the Gods is com­mon in ancient texts, and per­haps easier if the people you’re killing don’t have the men­tal capa­city to have Gods. If you want to fol­low Cath­olic doc­trine you could argue that this was when God chose to ensoul a spe­cies. If you prefer an athe­istic view you could take the view that the Neander­thals were the first vic­tims of religion.

His recent book The Human Story expands on this in more detail and it’s been avail­able sur­pris­ingly cheaply recently from Amazon’s mar­ket­place thing and Abebooks.
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