The Psychology of Religion

This post is the unedited transcript of a speech delivered at Renai Essense 2020, a freethought seminar organized by Bangalore Essense. Presentation slides are included.

I’ll start by defining some of the terms that we will be using which may not be part of our everyday vocabulary. While we are going through the glossary I’d like to take the opportunity to thank Essense for giving me this platform. It is so exciting to see the turnout today.

Researchers report that a chimpanzee will be willing to trade a banana in exchange for future favours like food, grooming or sex. But you can never get a chimpanzee to give you a banana in exchange for a favour in the next life. That is something unique to humans and we call it religion.

According to the Pew Research survey of 2015, only 16% of the world’s population is unaffiliated to any religion. Based on our 2011 Census, the figure for India might be below 1%. Why is religion so universal within the human species? And why is religion so unique to the human species? Today I want to take on the task of explaining the origins of religion from an evolutionary perspective.

Evolution by natural selection explains most human traits as adaptations, by asking the question “in what way could this trait have helped the survival or reproduction of the individual who had it?”. Let’s take an example. What could have been the advantage of bipedalism i.e. walking on two legs instead of four? Our ancestors who lived and hunted in the tall savannah grass could see further by standing on two feet. The hands were freed up for using hunting tools and for carrying babies.

But nothing comes without a cost and bipedalism has some nasty side-effects. It makes us prone to back pain because the entire weight of the spine is transferred to the last few vertebrae in the lower back.

Of course, it’s not only our bodies that are a product of evolution but also our minds. And today I’m going to argue that religion, and supernatural beliefs in general, are a by-product of certain adaptations. These adaptations have given us minds that are extremely powerful, but also extremely biased.

In the next few slides I will be introducing a few concepts whose relation to each other may not be obvious at first. But in the end I hope, the pieces of the puzzle will fall into place.

We’ll start by watching the famous Heider-Simmel Animation. It will run for about 45 seconds.

Most of us may have already concocted some story to explain what’s going on on the screen. For example, the big triangle is the villain. The small triangle is the hero trying to save the princess.

Now, there are at least three levels on which the events of the animation can be interpreted:

  1. The first is a literal interpretation. For example, the big triangle moved to the right, then the circle went inside the square box, and so on.
  2. The second level would be in terms of goal-directed behaviour like running, hiding and chasing.
  3. The third level would involve social attribution — an explanation of why the figures act as they do. For example, the big triangle is a jealous bully, the small triangle and circle are friends who want to run away together. The kind of stuff I made up earlier.

Constructing a story around the animation comes naturally to us. And even though the “characters” look nothing like people, we still manage to attribute anthropomorphic qualities to them.

The question is, how did we come to have this tendency?

Theory of Mind refers to an innate ability of all humans to attribute mental states to themselves and to others. It helps to predict the actions of other people by guessing their intentions and beliefs, which makes it very useful in a social setting.

Theory of Mind starts to develop in normal children by age 3 or 4, and can be tested by a False Belief Test. The child in this cartoon opens a box expecting to find Smarties (Gems/M&Ms), only to find pencils instead. The child is then asked what their friend, who has not opened the box, would assume its contents to be. The fact that the child fails to appreciate that someone else can have a false belief about what’s in the box, implies that their Theory of Mind is not yet fully developed. Most adults would answer “Smarties” in this case, not “Pencils”.

Passing a false belief test requires the ability to represent another person’s state of knowledge or state of mind. This sort of task seems so trivially easy to the average adult human, we tend to forget that it is an evolved adaptation. In fact autistic children mostly fail the false belief test, which goes to show that Theory of Mind is not equally well-developed in every individual.

Now let’s go back to our old friend, the hunter gatherer in the savannah. Say you are walking in the tall grass and you hear a rustling sound. It could just be the wind but it could also be a snake. Mistaking the wind for a snake is fairly harmless. You get startled, you laugh and you move on. But mistaking a snake for the wind could get you killed. Same goes for something that looks like a pair of tiger eyes stalking you.

In the environment of our ancestors, a failure to detect agents would have been very costly and this fact is coded into our instincts via natural selection. What do I mean by “agent”? I mean something that acts with intent or shows goal-directed behaviour. In short, something that appears to have a mind. Psychologists have a fancy name for this bias — Hyperactive Agency Detection Device.

This manifests in the form of strange biases like Pareidolia — the human tendency to see faces everywhere. Is that a face, or just three lines inside a circle? What about this one? And this one? The fact is, try as you might, you can’t help seeing a face there.

In fact, in 2004, a grilled cheese sandwich with the face of the Virgin Mary was sold for $28,000 on e-Bay!

Obviously our brains are wired to minimize false negatives when it comes to spotting a face. False positives don’t seem to matter at all. Why such a bias? To answer this question we need to first ask a very different question.

The human brain accounts for about 2% of our body weight but burns about 20% of total available calories. It’s a very expensive organ to run. The large heads of human infants make childbirth difficult and risky for the mother. In that case, how did we come to evolve such an oversized brain?

The Social Brain Hypothesis provides the most plausible explanation based on the evidence. It turns out that animals which live in large social groups have bigger brains. You can see the empirical relationship in this graph where each dot represents a species — actually we need to look at size of neocortex, not total brain size. The primate neocortex is disproportionately larger than what is required for navigating its physical environment. That is, for finding food, avoiding predators and so on. So then what is it for?

The answer? Our oversized brains are necessary for dealing with the demands of complex social interaction. That is what abilities like Theory of Mind are good for.

The scale of cooperation within a group is limited by every individual’s ability to handle social interaction. For example, hunting a much larger animal requires coordination within a larger group. And we know from the fossil record that early humans were capable of hunting mammoths the size of today’s elephants.

So we have large brains and large societies co-evolving, with an increase in one feeding an increase in the other. There are other factors like language and tool making that we won’t have time to go over today. Now it’s time to go back to our starting question — is religion a by-product of our social brain?

Selection pressures in the environment of our ancestors have given us minds that are optimized for understanding the minds of others. We are far better at social cognition (i.e. understanding what others know, think and feel) than we are at mechanical cognition (i.e. understanding how things work). As a result, attributing mental states becomes the default means for understanding the behaviour of anything. Not just people but also animals, machines, inanimate objects, even imaginary entities like nations and corporations.

Early humans projected their own desires, intentions and beliefs onto rocks, rivers, trees and dead ancestors as if these were capable of having mental states. They interpreted natural phenomena like rain, thunder and lightning, solar eclipses, earthquakes and the spread of disease as being the result of deliberate action by invisible agents. Agents that bear a suspicious resemblance to human beings.

Modern science explains the same natural phenomena in terms of mechanistic processes guided by rules. Rules that we can discover through observation and experiments.

Here’s an example to contrast these two ways of thinking. The planet Mars according to astrology, has certain anthropomorphic (or human-like) qualities and is capable of directly influencing human lives. The planet Mars according to astronomy, is a lump of rock that circles the Sun under the influence of gravity. Obviously the two descriptions cannot be reconciled. Or can they?

Some people still subscribe to the first account. Some people believe the second one. And, this being one of the spectacular feats of human cognition, many people subscribe to both views!

Ultimately, this is also the kind of thinking that lies at the bottom of ancient proto-religions like Animism, more informally termed “nature worship”, and the appearance of local deities linked to rivers, crops, animals, sun and moon etc. How did we get from these proto-religions to modern, organized religion? Well, that is the subject of another talk, another day. That’s all I have for now.

Thank you for your attention.



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