A recurring claim in a number of behavioural, cognitive and neuro-scientific literatures is that there is, or must be, a unidimensional ‘common currency’ in which the values of different available options are represented. There is striking variety in the quantities or properties that have been proposed as determinants of the ordering in motivational strength. Among those seriously suggested are pain and pleasure, biological fitness, reward and reinforcement, and utility among economists, who have regimented the notion of utility in a variety (...) of ways, some of them incompatible. This topic deserves philosophical attention for at least the following reasons. Repeated invocation of the ‘common currency’ idiom isn’t merely terminological coincidence because most of the claims are competing explanations either of manifest pattern in choices, or of order in the processes producing choice. We can’t suppose that the different currency claims within each area are compatible, because there are significant obstacles to identifying pairs of members of either the ‘pattern’ or ‘process’ group. There are, finally, seriously opposed positions about the relationships between the pattern facts and the process facts. There are philosophical positions both favouring and opposing a common currency. But direct consideration of the abstract relationships between claims about common currencies across scientific settings, and the arguments for and against these claims, is relatively rare. There is, though, much of philosophical interest to be found here. (shrink)

We conduct an experiment to investigate the degree to which deviations from exponential discounting can be accounted for by the hypothesis of hyperbolic discounting. Subjects are asked to choose between an earlier or later payoff in a series of 40 choice questions. Each question consists of a pair of monetary amounts determined by compounding a given base amount at a constant rate per period. Two bases (8 and 20 dollars), three compounding rates (low, medium and high) and three delays (2, (...) 4, and 6 weeks) are each used. There are also 2 initial periods (Today and 2 weeks) and there are two separate questionnaires, one with lower “realistic” compounding rates and the other with higher compounding rates, typical of those used in previous studies. We analyze the detailed patterns of choice in 6 groups of 6 related questions each (in which the base and rate is fixed but the initial period and delay varies), documenting the frequency of patterns consistent with exponential discounting and with hyperbolic discounting. We find that exponential discounting is the clear modal choice pattern in virtually all cases. Hyperbolic discounting is never the modal pattern (except in the sense that constant discounting is a special case of hyperbolic discounting). We also estimate a linear probability model that takes account of individual heterogeneity. The estimates show substantial increases in the probability of choosing the later option when the compounding rate increases, as one would expect. There are small, sometimes significant, increases in this probability when the delay is increased or the initial period is in the future. Such behavior is consistent with hyperbolic discounting, but can account for only a small proportion of choices. Overall, deviations from exponential discounting appear to be due to error, or to other effects not accounted for by hyperbolic discounting. Principal among these is an increase in later choices when the base is larger. (shrink)

Radical Behaviorism makes the implausible claim that “the appeal to mind explains nothing at all” (Skinner 1971, p. 186). Clearly, such a claim (if accepted) would lend strong support to the Skinnerian research program, if only because it would eliminate the major competition. But what support remains when such a claim is not accepted? This paper shall argue that the Skinnerian research program need not depend upon the supposition that there is something scientifically illicit or vacuous about the explanations offered (...) by mentalistic psychology. Distinguishing Radical Behaviorism from a position that grows out of Skinner’s writings from 1938 through 1950, it asserts that the latter position provides a conception of the behavior analytic program that is compatible with the basic claims of cognitive and folk psychology.We may give a rough definition of this position by following Cummins (1983) in distinguishing between two types of scientific theory. (shrink)

Maximization theory, which is borrowed from economics, provides techniques for predicing the behavior of animals - including humans. A theoretical behavioral space is constructed in which each point represents a given combination of various behavioral alternatives. With two alternatives - behavior A and behavior B - each point within the space represents a certain amount of time spent performing behavior A and a certain amount of time spent performing behavior B. A particular environmental situation can be described as a constraint (...) on available points (a circumscribed area) within the space. Maximization theory assumes that animals always choose the available point with the highest numerical value. The task of maximization theory is to assign to points in the behavioral space values that remain constant across various environmental situations; as those situations change, the point actually chosen is always the one with the highest assigned value. (shrink)