298 JONES Does this mean that people (and therefore their politics)are irrational? Not at all.People making choices are intendedly rational.They want to make rational decisions,but they cannot always do so. The implication for politics is that rational responses to the environment characterize decision making generally,but at points-often important points-rationality fails,and as a consequence there is a mismatch between the decision-making environment and the choices of the decision maker.We refer to this mismatch as "bounded rationality showing through"(Simon 1996b). asn This conception has an important implication.In structured situations,at euosjad least,we may conceive of any decision as having two components:environ- mental demands(seen by the individual as incentives,positive or negative) 豆 and bounds on adaptability in the given decision-making situation.Ideally,an analysis based on rational choice should be able to specify what the environ- 9086000 mental incentives are and to predict decisions based on those incentives.What cannot be explained is either random error (even the most rational of us may make an occasional mistake,but these are not systematic)or bounded rationality showing through.Standard statistical techniques give us the tools to distinguish systematic from random factors,so in principle it should be possi- ble to distinguish the rational,adaptive portion of a decision from bounds on rationality. popeojuo One may think ofany decision as arising from two sources.One is the exter- nal environment-how we respond to the incentives facing us.The other is the internal environment-those parts of our internal make-ups that cause us to 125-76 deviate from the demands of the external environment(Simon 1996b). We are not,however,thrown into a situation in which all residual system- atic deviations from rational choices are treated prima facie as bounded ra- 26661 tionality.A very limited set of facets of human cognitive architecture accounts for a very large proportion of the deviations from adaptation.These may be placed into two classes:procedural limits,which limit how we go about mak- ing decisions,and substantive limits,which affect particular choices directly. Of procedural limits,I cite two as being extraordinarily important in struc- 台 tured,institutional settings (such as voting in mass publics or in legislative bodies),attention and emotion.Of substantive limits,I cite but one-the ten- dency of humans to "overcooperate,"that is,to cooperate more than strict adherence to rationality would dictate. The primary argument in this essay is that most behavior in politics is B adaptive and intendedly rational but that limits on adaptive behavior,imposed by human cognitive/emotional architecture,may be detected in even the most stable of environments.I advocate a research strategy that explicitly divides political action into the two categories of intended rationality and deviations from(or bounds on)intended rationality and explores empirically the implica- tions for the outputs of institutions and the institutional processes responsibleDoes this mean that people (and therefore their politics) are irrational? Not at all. People making choices are intendedly rational. They want to make rational decisions, but they cannot always do so. The implication for politics is that rational responses to the environment characterize decision making generally, but at points—often important points—rationality fails, and as a consequence there is a mismatch between the decision-making environment and the choices of the decision maker. We refer to this mismatch as “bounded rationality showing through” (Simon 1996b). This conception has an important implication. In structured situations, at least, we may conceive of any decision as having two components: environ￾mental demands (seen by the individual as incentives, positive or negative) and bounds on adaptability in the given decision-making situation. Ideally, an analysis based on rational choice should be able to specify what the environ￾mental incentives are and to predict decisions based on those incentives. What cannot be explained is either random error (even the most rational of us may make an occasional mistake, but these are not systematic) or bounded rationality showing through. Standard statistical techniques give us the tools to distinguish systematic from random factors, so in principle it should be possi￾ble to distinguish the rational, adaptive portion of a decision from bounds on rationality. One may think of any decision as arising from two sources. One is the exter￾nal environment—how we respond to the incentives facing us. The other is the internal environment—those parts of our internal make-ups that cause us to deviate from the demands of the external environment (Simon 1996b). We are not, however, thrown into a situation in which all residual system￾atic deviations from rational choices are treated prima facie as bounded ra￾tionality. A very limited set of facets of human cognitive architecture accounts for a very large proportion of the deviations from adaptation. These may be placed into two classes: procedural limits, which limit how we go about mak￾ing decisions, and substantive limits, which affect particular choices directly. Of procedural limits, I cite two as being extraordinarily important in struc￾tured, institutional settings (such as voting in mass publics or in legislative bodies), attention and emotion. Of substantive limits, I cite but one—the ten￾dency of humans to “overcooperate,” that is, to cooperate more than strict adherence to rationality would dictate. The primary argument in this essay is that most behavior in politics is adaptive and intendedly rational but that limits on adaptive behavior, imposed by human cognitive/emotional architecture, may be detected in even the most stable of environments. I advocate a research strategy that explicitly divides political action into the two categories of intended rationality and deviations from (or bounds on) intended rationality and explores empirically the implica￾tions for the outputs of institutions and the institutional processes responsible 298 JONES Annu. Rev. Polit. Sci. 1999.2:297-321. Downloaded from arjournals.annualreviews.org by UNIVERSITY OF WASHINGTON - HEALTH SCIENCES LIBRARIES on 09/25/06. For personal use only