The problem with economics, however, is that while it’s got theories, they are, by and large, not theories about humans.
The discipline which was, at least, intended to provide the theoretical grounding for psychology as a whole was evolutionary psychology. The best summary of the motivation for, and conceptual basis of, evo-psych is the following, written by great cognitive psychologist Roger Shepard in his paper “The Perceptual Organization of Colors: An Adaptation to Regularities of the Terrestrial World?” (1992; this paper was included as a chapter in The Adapted Mind, probably the most import text in evo psych):
STRUCTURE IN HUMAN PERCEPTION AND COGNITION IN GENERAL
For over a century, psychological researchers have been probing the structures and processes of perception, memory, and thought that mediate the behaviors of humans and other animals. Typically, this probing has taken the form of behavioral experiments suggested by evidence from one or more of three sources: (a) introspections into one’s own experience and inner processes, (b) information gleaned about the anatomy or physiology of the underlying physical mechanisms, and (c) results obtained from previous behavioral studies. More recently, in seeking to understand not only the nature but also the origins of psychological principles, some of us have been turning to a fourth source for guidance—namely, to the ecological properties of the world in which we have evolved and to the advantages to be realized by individuals who have genetically internalized representations of those properties.
Taken by themselves, findings based on introspective, behavioral, and physiological evidence alike, however well established and mutually consistent they may be, remain as little more than “brute facts” about the human or animal subjects studied. What such findings reveal might be merely arbitrary or ad hoc properties of the particular collection of terrestrial species investigated. Even our own perceptual and cognitive capabilities, as much as our own bodily sizes and shapes, may be the products of a history of more or less accidental circumstances peculiar to just one among uncounted evolutionary lines. Certainly, these capabilities do not appear to be wholly dictated by what is physically possible.
The following are just a few of the easily stated and well known of our perceptual/cognitive limitations, as these have been demonstrated under highly controlled but nonnaturalistic laboratory conditions:
Although a physical measuring instrument can reliably identify a vast number of absolute levels of a stimulus, we reliably identify only about seven (Miller, 1956).
Although a physical recording instrument can register a vast number of dimensions of variation of the spectral composition of light, the colors we experience vary, as I have already noted, along only three independent dimensions (Helmholtz, 1856–1866; Young, 1807).
Although the red and violet spectral colors differ the most widely in physical wavelength, these colors appear more similar to each other than either does to the green of an intermediate wavelength (leading, as noted, to Newton’s color circle).
Although a camera can record and indefinitely preserve an entire scene in a millisecond blink of a shutter, the “iconic” image that our visual system retains from a single brief exposure decays in less than a second and, during this time, we are able to encode only about four or five items for more permanent storage (Sperling, 1960).
Although a computer can store an essentially unlimited number of unrelated items for subsequent retrieval, following a single presentation, we can reliably recall a list of no more than about seven items (Miller, 1956).
Although a computer could detect correlations between events separated by any specified time interval and in either order of occurrence, in virtually all animals with nervous systems, classical conditioning generally requires that the conditioned stimulus last for a short time and either be simultaneous with the unconditioned stimulus or precede it by no more than a few seconds (Pavlov, 1927, 1928).
Although a computer can swiftly and errorlessly carry out indefinitely protracted sequences of abstract logical operations, we are subject to systematic errors in performing the simplest types of logical inferences (e.g., Tversky & Kahneman, 1974; Wason & Johnson-Laird, 1972; Woodworth & Sells, 1935)—at least when these inferences are not of the kind that were essential to the fitness of our hunter-gatherer ancestors during the Pleistocene era (Cosmides, 1989).
Our performance in a natural setting is, however, a very different matter. There, our perceptual and cognitive capabilities vastly exceed the capabilities of even the most advanced artificial systems. We readily parse complex and changing visual scenes and auditory streams into spatially localized external objects and sound sources. We classify those objects and sources into natural kinds despite appreciable variation in the individual instances and their contexts, positions, or conditions of illumination. We infer the likely ensuing behaviors of such natural objects—including the recognition of animals and anticipation of their approach or retreat, the recognition of faces and interpretation of their expressions, and the identification of voices and interpretation of their meanings. We recode and transfer, from one individual to another, information about arbitrary or possible states of affairs by means of a finite set of symbols (phonemes or corresponding written characters). And we plan for future courses of action and devise creative solutions to an open class of real-world problems.
To the extent that psychological science fails to identify nonarbitrary reasons or sources for these perceptual/cognitive limitations and for these perceptual/cognitive capabilities, this science will remain a merely descriptive science of this or that particular terrestrial species. This is true even if we are able to show that these limitations and capabilities are consequences of the structures of underlying neurophysiological mechanisms. Those neurophysiological structures can themselves be deemed nonarbitrary only to the extent that they can be seen to derive from some ultimately nonarbitrary source.
Where, then, should we look for such a nonarbitrary source? The answer can only be, “In the world.” All niches capable of supporting the evolution and maintenance of intelligent life, though differing in numerous details, share some general—perhaps even universal—properties. It is to these properties that we must look for the ultimate, nonarbitrary sources of the regularities that we find in perception/cognition as well as in its underlying neurophysiological substrate.
Some of the properties that I have in mind here are the following (see Shepard, 1987a, 1987b, 1988, 1989): Space is three-dimensional, locally Euclidean, and endowed with a gravitationally conferred unique upward direction. Time is one-dimensional and endowed with a thermodynamically conferred unique forward direction. Periods of relative warmth and light (owing to the conservation of angular momentum of planetary rotation) regularly alternate with periods of relative coolness and darkness. And objects having an important consequence are of a particular natural kind and therefore correspond to a generally compact connected region in the space of possible objects—however much those objects may vary in their sensible properties (of size, shape, color, odor, motion, and so on).
Among the genes arising through random mutations, then, natural selection must have favored genes not only on the basis of how well they propagated under the special circumstances peculiar to the ecological niche currently occupied, but also, as I have argued previously (e.g., Shepard, 1987a), even more consistently in the long run, according to how well they propagate under the general circumstances common to ail ecological niches. For, as an evolutionary line branches into each new niche, the selective pressures on gene propagation that are guaranteed to remain unchanged are just those pressures that are common to all niches.
(Shepard then goes on to describe the deep questions which underlie his own work on color perception, one of which the rest of the paper is dedicated to examining and answering. I highly recommend reading the whole thing.)
The problem with economics, however, is that while it’s got theories, they are, by and large, not theories about humans.
To be more precise, economics does seem to have a lot of useful and powerfully predictive theories about groups of humans, but not so much about individuals.
There is a ton of variation in how any given person might act in a certain situation, but when you consider the economy as a whole (as in macroeconomics), the financial markets (as in… financial economics), or even just the market for a single good (as in microeconomics), the noise mostly cancels out and the overall effect can usually be modeled accurately and successfully by considering idealized notions such as purely utility-maximizing self-interested consumers.
But if you try to deeply study a single mind, you no longer benefit from this concentration of measure and your 1st order approximation will often be inaccurate and miscalibrated.
The problem with economics, however, is that while it’s got theories, they are, by and large, not theories about humans.
The discipline which was, at least, intended to provide the theoretical grounding for psychology as a whole was evolutionary psychology. The best summary of the motivation for, and conceptual basis of, evo-psych is the following, written by great cognitive psychologist Roger Shepard in his paper “The Perceptual Organization of Colors: An Adaptation to Regularities of the Terrestrial World?” (1992; this paper was included as a chapter in The Adapted Mind, probably the most import text in evo psych):
(Shepard then goes on to describe the deep questions which underlie his own work on color perception, one of which the rest of the paper is dedicated to examining and answering. I highly recommend reading the whole thing.)
To be more precise, economics does seem to have a lot of useful and powerfully predictive theories about groups of humans, but not so much about individuals.
There is a ton of variation in how any given person might act in a certain situation, but when you consider the economy as a whole (as in macroeconomics), the financial markets (as in… financial economics), or even just the market for a single good (as in microeconomics), the noise mostly cancels out and the overall effect can usually be modeled accurately and successfully by considering idealized notions such as purely utility-maximizing self-interested consumers.
But if you try to deeply study a single mind, you no longer benefit from this concentration of measure and your 1st order approximation will often be inaccurate and miscalibrated.