Thinking About Modules

November 21, 2011

In a recent Wall Street Journal review article, Raymond Tallis expresses dissatisfaction with what he calls “biologism” – the view that nothing fundamental separates humanity from animality. Biologism is described as having two “cardinal manifestations”.

The first is that the mind is the brain, or its activity. This view is held to have the consequence that one of the most powerful ways to understand ourselves is through scanning the brain’s activities.

The second manifestation of biologism is the claim that “Darwinism explains not only how the organism Homo sapiens came into being (as, of course, it does) but also what motivates people and shapes their day-to-day behavior”.

Tallis suggests that putting these ideas together leads to the following view. The brain evolved under natural selection, the mind is the (activities of the) brain, our behavior depends on the mind/brain, therefore the mind and our behavior can be explained by evolution. A further implication is claimed, namely, that “The mind is a cluster of apps or modules securing the replication of genes that are expressed in our bodies”. Studying the mind can be broken down into studying (by brain scans) the operation of these modules.

Tallis laments the wide acceptance of this way of looking at ourselves. He affirms that brain activity is a necessary condition of all of our consciousness, but holds that “many aspects of everyday human consciousness elude neural reduction”.

But how could aspects of our consciousness elude neural reduction, if everything in our consciousness depends on the workings of the brain? Tallis answers: “For we belong to a boundless, infinitely elaborated community of minds that has been forged out of a trillion cognitive handshakes over hundreds of thousands of years. . . . Because it is a community of minds, it cannot be inspected by looking at the activity of the solitary brain.”

This statement, however, is not an answer to the question of how aspects of our consciousness can elude neural reduction. It explains, instead, why we cannot understand facts about societies by looking at a solitary brain, and why we cannot reconstruct the evolutionary history of our species by looking at the brain of one individual. But the question about elusiveness of neural reduction concerns the consciousness of individuals. It’s about how individual minds work, and what gives rise to each person’s behavior.

Aside from rare cases of feral children, individuals grow up in societies. Even so, their motivations and behavior depend on their individual brains. Individuals must have some kind of representation of societal facts and norms in their own brains, if those brains are to produce behaviors that are socially appropriate and successful. At present, alas, we do not understand what form those representations take, nor how they are able to contribute, jointly with other representations, to intelligent behavior. But the question of how the individual mind works is a clear one, and the search for an answer is one of the most exciting inquiries of our time.

Despite my dissatisfaction with Tallis’s account, I am sympathetic to some of his doubts about reduction of motivation and behavior to the operations of modules. The true source of the problem, however, is not our attention to the mind/brain of solitary individuals.

The real problem is, instead, uncritical acceptance of modules. The modular way of looking at things does not follow from Tallis’s two cardinal manifestations. They say, in sum, that whatever we think and whatever we do depends on the activities of a brain that developed under principles of Darwinian evolution. They do not say one word about modules. They do not imply any theory of how the evolved brain does what it does.

These remarks are in no way a denial of modules, and in some cases, there is very good reason to accept them. But, even accepting that there are many modules, it does not follow that for any given motivation or behavior, X, there is a module that is dedicated to providing X – i.e., that functions to provide X and does not do anything else. Moreover, it is clear that our evolved brain allows for learning. If we learn two things, they may be related, and if we recognize a relation among things that we had to learn in the first place, there cannot be a module for recognizing that relation.

Caution about introducing modules for specific mental or behavioral features that may interest us is compatible with supposing not only that there are many modules, but even with supposing that operations of several modules is required for everything we do. That’s because plurality of modules carries with it the possibility of variability in how they are connected. Such variability may depend on genetic differences, developmental differences, and/or differences in learning. In any case of combined action of several modules, therefore, there will be no simple relation between a motivation or a behavior and a single module, nor any simple relation between a motivation or behavior and a collection of modules.

So, even granting Tallis’s two cardinal manifestations and a commitment to extensively modular brain organization, we cannot expect any simple relation to hold between some ability that interests us and the operation of a module dedicated to that ability. So, I agree with Tallis that we should be suspicious of facile “discoveries” of a module for X, where X may be, e.g., an economic behavior or an aesthetic reaction. But I think that the complexities that lie behind this suspicion are to be found in the complexity of the workings of individual brains. Our social relations with others provides distinctive material for us to think about, but they will not explain how we do our thinking about them.

[Raymond Tallis, “Rethinking Thinking”, The Wall Street Journal for November 12-13, 2011, pp. C5 and C8. Readers of _Your Brain and You_ will be familiar with reasons for regarding sensations as effects of, rather than the same thing as, neural activities; but this kind of non-reducibility is not relevant to the issues discussed in this post. They will also be aware of reasons for saying that we do not presently understand how individual minds work.]

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