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How evolution has shaped perception

You might have come across one of those posts on social media that ask you to read a paragraph at the end of which you’re told that you missed some articles that were there in the text.

You then read the paragraph again and find that you did indeed miss that extra “the” or “a” during the previous reading. How could you be so blind?

If your mind omits bits of information in a paragraph does it do the same with the world?

Is our perception of the reality that we see every day equally flawed?

Ignoring the unimportant

It’s easy to understand why your brain skips redundant articles in a paragraph. They’re not important as they interfere with your ability to understand the message of the paragraph as quickly as possible.

Our brains evolved for Stone Age where the ability to make quick decisions likely contributed to increased fitness (i.e. better chances of survival and reproduction). Reading a paragraph accurately was comparatively unimportant as far as fitness was concerned. In fact, writing was invented much later.

Therefore, when presented with a paragraph, all your mind cares about is interpreting the message contained within it as quickly as possible. It ignores the minor errors because wasting time and energy on them could prove to be costly.

The consequences of obtaining the right information as quickly as possible could have meant the difference between life and death in our ancestral environments.


snake's perception
How a snake sees the world.


Fitness comes first

Not only have our brains evolved to make quick decisions, they’ve also evolved to parse that information from the environment which has some bearing on our survival and reproduction i.e on our fitness.

In other words, your mind is sensitive to those cues in the environment that have the potential to influence your survival and reproduction.

This is why we’re quick to detect food and attractive people in the environment but are unable to spot an extra “the” in a paragraph. Knowing where food and potential mates are can contribute to our fitness.

Similarly, when you hear the ruffle of a plastic wrapper you assume the presence of food until your friend explicitly shows you that the wrapper contains a non-edible phone charger.

Fitness beats truth

When we look at other animals we often see that their perceptions of the world are entirely different from ours. Snakes, for example, can see in the dark as you would via an infrared camera. Similarly, bats construct their image of the world using sound waves.

In general, every living organism sees the world that best helps it survive and reproduce. They need not see the true picture of the world. 

Evolution by natural selection, in general, favors perceptions that are tuned to fitness, not to the objective truth of the world.

Even though it may seem like that we humans see the truth of what is out there but the fact remains that all that we see comprises only a small part of the electromagnetic spectrum. In other words, we only see a very small part of what’s really out there but this small part is enough to enable us to survive and thrive.

Experiments based on evolutionary game models have shown that accurate perceptual strategies do not out-compete inaccurate perceptual strategies in conferring fitness. In fact, true perceptual strategies that provide an accurate view of the world were swiftly driven to extinction in these experiments.

Is any of it real?

Some researchers have taken this idea that we don’t see the world accurately to the extreme and put forward what’s known as the Interface Theory of Perception.

According to this theory, everything that we see is there because we’re evolved to see just that. What we’re perceiving is an interface, not the real reality of things.

That pen you see on your table is not really a pen. Just like every other object that you see, it has a deeper reality that you can’t perceive simply because your naturally selected brain is incapable of perceiving it.



References:

Mark, J. T., Marion, B. B., & Hoffman, D. D. (2010). Natural selection and veridical perceptions. Journal of Theoretical Biology266(4), 504-515.

Hoffman, D. D. (2009). The user-interface theory of perception: Natural selection drives true perception to swift extinction. In In.

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