Feb 06 2017

Why Are We Conscious?

Dennet-Book 2017In Daniel Dennett’s latest book,From Bacteria to Bach and Back: The Evolution of Minds, Dennett explores a number of issues surrounding consciousness. I have not yet completed the book and so may come back to it again, but wanted to discuss one topic that Dennett covers – why are we conscious in the first place?

Dennett makes a distinction between competence and comprehension. Competence is the ability to perform some task, while comprehension is understanding the task and the process. The former is unconscious, while the latter is conscious.

This touches on Chalmers’ “P-zombie” problem – if we can imagine an organism that can do everything a human does without experiencing its own existence (a philosophical zombie), then why did consciousness evolve at all? There are several possible solutions to this problem. The first is that humans were “designed” to be conscious by whatever agent made us. This introduces unnecessary elements and contradicts established science, so I think we can set that aside.

The second solution is that consciousness is an epiphenomenon. We don’t need to be conscious, but we evolved consciousness as an evolutionary accident. This may be true, but is unsatisfying as it just side-steps the question of what use is consciousness.

The third solution, which I find compatible with the evidence and compelling, is that consciousness is inherent to the functioning of our brains and brings with it specific advantages.

Dennett focuses on two aspects of human behavior that he feels were critical in bootstrapping human-level consciousness – social interaction and language (which themselves are related).

Humans are intensely social creatures. This was one of our major evolutionary adaptations, we live and hunt in groups. The most obvious function that aids social interaction is communication, which is where language comes in. I think at least as important as language is that social creatures need to have what psychologists refer to as a theory of mind, which is an understanding that other people have thoughts, feelings, and motivations of their own.

If you are living in a social group, there is an obvious advantage to being able to predict that another member of that group is going to help you in a certain situation, or that they may be out to get you. Is that a friend or enemy? How will they react if I engage in a certain behavior?

At the group level, everyone will have a better chance of surviving if they get along, and can understand each other’s behavior and motivations. Group cohesion, including obvious things like hunting together, requires coordination of efforts. This not only benefits from more and more sophisticated language, but also from the ability to learn how to do the things that the group does – to mimic.

Mimicking, reading and conveying emotions and intentions, group cohesion, and communication all play off each other. Humans have the ability to feel what other people feel, to move like other people, talk like them, express emotions like them, even to think like them. We call this culture.

Culture is a powerful thing. Think about the people you know – they belong to a family culture, a regional culture, and a national culture. Think about your interactions with people from completely different cultures – everything they do is subtly different. Yes, there are human universals, but the effect of culture cannot be overestimated. How close we stand to other people, level of eye contact, how emotionally expressive we are, our posture, how we walk, eat, and of course our language and accents are all learned by copying those around us. Our brains literally mirror the brains of others in our group.

In order for me to predict what someone else might do based upon what I think they are feeling, what they know, their motivations, and their past behavior, I need to have an understanding of their mind. I know they are conscious because I am conscious.

Someone defending Chalmers might say that an unconscious predictive algorithm might do just as well, but that misses the point. Such an algorithm can only work because humans are conscious. Because we feel and think, and that drives our behavior. Further, the best algorithm for predicting how humans feel, think, and behavior is another human with a similar brain that thinks, feels, and behaves in a similar fashion. We literally run a model of other people in our own heads – we imagine how we might feel and behave as a way of predicting the actions of others.

Psychologists have a word for this too – projection. People are still individuals, we are not exact copies of each other. So predicting what someone else will do based upon what we would do is imperfect. It is also extremely revealing. Often, when we speculate about the motivations of others were are really just revealing our own motivations that we then project onto others. It takes insight and self-awareness to separate these two things.

The theory of mind and the demands of being a social creature are only part of the equation. Bees are social creatures, but they collaborate entirely with instinct. Humans also developed language, and Dennett follows Chomski on this topic – the idea that language is uniquely human and is critical to being human.

Perhaps we first started communicating with each other with simple and obvious hand signals. However, many animals use sounds for communication (warning sounds, mating sounds) and so our ancestors probably did this also. Eventually they started to use more and more sophisticated sounds and gestures to communicate more and more complex information.

The interaction of intense social interaction with evolving language was like rocket fuel to human consciousness. Out of this mix evolved culture. Dennett gets into the notion of memes, which he thinks of as tiny units of cultural information. The notions of memes has many critics, but I think this is actually incidental to Dennett’s main points. You don’t need to call them memes, or even to have a concept of a cultural unit. You can think of culture as a mish-mash of ideas and behaviors with no distinguishable units, and Dennett’s main point would still hold.

Essentially you have a positive feedback loop with language, culture, social interaction, and intellectual sophistication. The result was that our proto-human ancestors dramatically increased the size of their brains in a few million years. The evolutionary pressures for greater intelligence were apparently massive, once those factors all came into play.

The result was a creature that could think in words, that could think about what other creatures felt and thought, and that could contemplate, therefore, its own feelings and thoughts.

That’s consciousness.

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