Factors of production in biology, neuroscience, and economics

In the foreword to the second edition of Susan Oyama’s The Ontogeny of Information, R.C. Lewontin observes a problem in understanding the emergence of biological forms:

Mendel himself slipped over into an explanation of the origin of form itself by postulating that the red- and white-flowered plants had mysterious ‘‘factors’’ for redness and whiteness. Moreover, the factor for redness had a power that enabled it to dominate the factor for whiteness when the two were present in the same plant.

Today, this is the commonplace understanding of genes, especially among laypersons like myself: genes do the things that we observe. If you have ears, there are genes for ears that cause ears to happen. If you like the taste of sugar, there are sugar-tasting genes that make your tongue be like that. And so on.

There is a related methodological fallacy in studying how genes work. If you remove a gene, and ears no longer grow, was that gene the ears gene? If you edit a gene, and sugar now tastes like ash, was that the sugar-tasting gene? It seems so, but not necessarily. For example, suppose that you have a house that is insulated from the cold, and then you knock a hole in one of the four walls, causing the house to quickly become as chilly inside as it is outside. Was that wall then the weather insulating wall? Of course not—all four walls play vital roles. There is no weather insulation without all of them present and doing their jobs, a phenomenon that Esther Thelen called multicausality.

Neuroscience has faced an analogous challenge. Historically, psychologists have been tempted to abscribe an observed psychological phenomenon to a mechanism in the brain that produces that phenomenon—so an emotion is caused by a corresponding emotion circuit, memory is caused by a memory part of the brain, language is caused by a language part of the brain, vision is caused by a vision part of the brain, etc.

And there is the same methodological challenge in neuroscience as in genetics: if you slice out some part of the brain, and a behavior stops being exhibited, did that part of the brain cause that behavior? It’s tempting to try to understand complex systems by studying them the way you figure out the circuits in your home: knocking them out one at a time and seeing what turns off. But this just isn’t methodologically valid. What a part does depends on everything it interacts with in the body and the external environment.

The production of biological and psychological phenomena cannot be attributed to specific factors of production that are dedicated to those phenomena. Ears aren’t caused by an ear gene; fear isn’t caused by a fear circuit. Much more general processes underlie both: interoception-and-allostasis, or the activity of the internal economy, producing stuff that observers then break apart into different categories.

Economists have certainly struggled with some of the same methodological and theoretical issues, but not to the same degree. The factors of production in economics have always been understood to be very general—labor and capital—and capable of producing many different things simply by being applied in different combinations in different circumstances. The existence of the pencil industry, for example, isn’t caused by a specific pencil factor of production but is just one of the things that happens when labor and capital interact in various ways in an environment. Economists can then attribute the phenomenon of transforming capital and labor into specific outputs like pencils to the magic of human ingenuity. It’s possible that adopting the economic perspective on factors of production may prove useful in both biology and psychology: for example, the cells might be seen as laborers, and their proteins their capital.