Endogenous reward (intrinsic reward at will) is a fiat currency that is occasioned by steps toward any goals which are challenging and/or uncommon enough to prevent its debasement by inflation. A “theory of mental computational processes” should propose what properties let goals grow from appetites for endogenous rewards. Endogenous reward may be the universal selective factor in all modifiable mental processes.

Natural selection is slow, so behavioral goals must be based on patterns of reward. Addictions are rewarded in the same way as adaptive choice, so they can be distinguished only by their time course. In addition, the reward process is more plastic than is generally recognized, so abstract goals are shaped by the “legibility” of their proxies.

Shortcuts to goals are rewarded by faster attainment and punished by more frequent failure, so selection of the various kinds – heuristics, cached sequences (habits or macros), gut instincts – depends on reward history just like other kinds of choice. The speeds of shortcuts lie on continua along with speeds of deliberation, and these continua have no obvious separation points.

Frames group choices into categories, thus modifying the incentives for them. This effect makes framing itself a motivated choice rather than a neutral cognition. In particular, framing an inferior choice with a high short-term payoff as part of a broad category of choices recruits incentive to reject it; but this must be motivated by its being a test case.

Twenty-six commentators from several disciplines have written on the assumption that choice is determined by comparative valuation in a common denominator of reward, the “competitive marketplace.” There was no apparent disagreement that prospective rewards are discounted hyperbolically, although some found that the resulting predictions could come just as well from other models, including the interpretation of delay as risk and analysis in terms of hot versus cold valuation systems. Several novel ideas emerged.

Most authors who discuss willpower assume that everyone knows what it is, but our assumptions differ to such an extent that we talk past each other. We agree that willpower is the psychological function that resists temptations – variously known as impulses, addictions, or bad habits; that it operates simultaneously with temptations, without prior commitment; and that use of it is limited by its cost, commonly called effort, as well as by the person's skill at executive functioning. However, accounts are usually not clear about how motivation functions during the application of willpower, or how motivation is related to effort. Some accounts depict willpower as the perceiving or formation of motivational contingencies that outweigh the temptation, and some depict it as a continuous use of mechanisms that interfere with re-weighing the temptation. Some others now suggest that impulse control can bypass motivation altogether, although they refer to this route as habit rather than willpower.

It is argued here that willpower should be recognized as either or both of two distinct functions, which can be called resolve and suppression. Resolve is based on interpretation of a current choice as a test case for a broader set of future choices, which puts at stake more than the outcome of the current choice. Suppression is inhibiting valuation of (modulating) and/or keeping attention from (filtering) immediate alternatives to a current intention. Perception of current choices as test cases for broader outcomes may result in reliable preference for these outcomes, which is experienced as an effortless habit – a successful result of resolve, not an alternative method of self-control. Some possible brain imaging correlates are reviewed.

An intertemporal bargaining model of commitment does not entail the interaction of parts within the person as Rachlin claims, and is needed to explain properties of “ordinary” self-control that his molar generalization model does not predict.

“Negative” emotions are never purely negative. They attract attention at the very least and often stay attractive enough to make rehearsing them an addictive activity. As the authors point out, they also counteract a relentless tendency for positive emotions to become boring. Analysis in terms of reward suggests why this tendency occurs and how symbiosis with negative emotions may arise, in art and in life.

Authors of non-liberal proposals experience more collegial objections than others do. These objections are often couched as criticism of determinism, reductionism, or methodological individualism, but from a scientific viewpoint such criticism could be easily answered. Underneath it is a wish to harness scientific belief in service of positive social values, at the cost of reducing objectivity.

The role of emotional trauma in psychopathology is limited. One additional mechanism is predictable from hyperbolic discounting: When a person uses willpower to control urges each success or failure takes on extra significance through recursive self-prediction, potentially motivating several constricting defense mechanisms. The need for eliciting emotion in psychotherapy is as the authors say it is, but their hypothesis about reconsolidation of memories adds no explanatory power.

Selfish Goal Theory is compatible with a behaviorally based theory that recognizes mental processes as behaviors. Both envision choices as made by the competition of purposive processes, which are autonomous in that they are not coordinated by an agentic “self.” However, the survival of mental processes – termed “goals” or “interests,” respectively – depends on a well-documented active mechanism: reward.

Self-control is a necessary component of subjective effort, but it depends only on farsighted motivation, with no additional, depletable resource. The aversiveness of boring tasks probably comes from their interference with endogenous reward, a new and potentially controversial concept. The self-control needed to stick with any kind of aversive experience increases as the values of the competing motives draw closer together.

A climate that is too cold to grow crops for part of the year demands foresight and self-control skills. To the extent that a culture has developed intertemporal bargaining, its members will have more autonomy, but pay the cost of being more compulsive, than members of societies that have not. Monetary resources will be a consequence but will also be fed back as a cause.

To the extent that acting fairly is in an individual's long-term interest, short-term impulses to cheat present a self-control problem. The only effective solution is to interpret the problem as a variant of repeated prisoner's dilemma, with each choice as a test case predicting future choices. Moral choice appears to be the product of a contract because it comes from self-enforcing intertemporal cooperation.

Science has needed a dispassionate valuation of psychoactive drugs, but a motivational analysis should be conducted with respect to long-term reward rather than reproductive fitness. Because of hyperbolic overvaluation of short-term rewards, an individual's valuation depends on the time she forms it and the times she will revisit it, sometimes making her best long-term interest lie in total abstinence.

The matching law accounts for both addictive behavior and the usefulness of a person's evaluating choices in overall categories. To explain why overall bookkeeping, once learned, does not easily win out over local bookkeeping, another implication of matching is needed: intertemporal bargaining. The role of melioration, though probably important for new addiction is separate.