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Pigeons and undergraduates learned conditional discriminations involving multiple spatially separated stimulus dimensions. Under some conditions, the dimensions were made available sequentially. In 3 experiments, the dimensions were all perfectly valid predictors of the response that would be reinforced and mutually redundant; in 2 others, they varied in validity. In tests with stimuli in which 1 of the 3 dimensions took an anomalous value, most but not all individuals of both species categorized them in terms of single dimensions. When information was delivered as a function of the passage of time, some students, but no pigeons, waited for the most useful information, especially when the cues differed in objective validity. When the subjects could control information delivery, both species obtained information selectively. When cue validities varied, almost all students tended to choose the most valid cues, and when all cues were valid, some chose the cues by which they classified test stimuli. Only a few pigeons chose the most useful information in either situation. Despite their tendency to unidimensional categorization, the pigeons showed no evidence of rule-governed behavior, but students followed a simple 'take-the-best' rule. Keywords: pigeon, undergraduate, categorization, one-reason decision making, information search DOI: 10.1037/a0016851

Pigeons (Columba livia), gray squirrels (Sciurus carolinensis), and undergraduates (Homo sapiens) learned discrimination tasks involving multiple mutually redundant dimensions. First, pigeons and undergraduates learned conditional discriminations between stimuli composed of three spatially separated dimensions, after first learning to discriminate the individual elements of the stimuli. When subsequently tested with stimuli in which one of the dimensions took an anomalous value, the majority of both species categorized test stimuli by their overall similarity to training stimuli. However some individuals of both species categorized them according to a single dimension. In a second set of experiments, squirrels, pigeons, and undergraduates learned go/no-go discriminations using multiple simultaneous presentations of stimuli composed of three spatially integrated, highly salient dimensions. The tendency to categorize test stimuli including anomalous dimension values unidimensionally was higher than in the first set of experiments and did not differ significantly between species. The authors conclude that unidimensional categorization of multidimensional stimuli is not diagnostic for analytic cognitive processing, and that any differences between human's and pigeons' behavior in such tasks are not due to special features of avian visual cognition. Keywords: pigeon, undergraduate, eastern gray squirrel, categorization, rule-governed behavior DOI: 10.1037/a0016216

Our response amplifies our ease that money is best seen as both a drug and a tool. Some commentators challenge our core assumptions: In this response we, therefore, explain in more detail why we assume that money is an exceptionally strong motivator, and that a biological explanation of money motivation is required. We also provide evidence to support those assumptions. Other commentators criticise our use of the drug metaphor, particularly arguing that it is empirically empty; and in our response we seek to show how it can be submitted to test--aided by some commentaries which suggest such tests. In addition, we explain, with evidence, why we do not think that the notion of money as a generalised conditioned reinforcer provides a satisfactory alternative to the tool/drug account. The largest group of commentaries suggests alternative instincts on which the drug-like effects of money might be based, other than the reciprocation and play instincts we propose; in our response, we explain why we still prefer our original proposals, but we accept that alternative or additional instincts may indeed underlie money motivation. A final group of commentaries carries the argument further, suggesting extensions to the tool/drug model, in ways with which we are broadly in sympathy. The purpose of the tool and drug metaphors is to encourage reflection on the biological origins of money motivation, and to that extent at least we believe that they have succeeded.

Why are people interested in money? Specifically, what could be the biological basis for the extraordinary incentive and reinforcing power of money, which seems to be unique to the human species? We identify two ways in which a commodity which is of no biological significance in itself can become a strong motivator. The first is if it is used as a tool, and by a metaphorical extension this is often applied to money: it is used instrumentally, in order to obtain biologically relevant incentives. Second, substances can be strong motivators because they imitate the action of natural incentives but do not produce the fitness gains for which those incentives are instinctively sought. The classic examples of this process are psychoactive drugs, but we argue that the drug concept can also be extended metaphorically to provide an account of money motivation. From a review of theoretical and empirical literature about money, we conclude that (i) there are a number of phenomena that cannot be accounted for by a pure Tool Theory of money motivation; (ii) supplementing Tool Theory with a Drug Theory enables the anomalous phenomena to be explained; and (iii) the human instincts that, according to a Drug Theory, money parasitizes include trading (derived from reciprocal altruism) and object play. Keywords: economic behaviour; evolutionary psychology; giving; incentive; money; motivation; play; reciprocal altruism

Stimulus sets defined in terms of artificial polymorphous concepts have frequently been used in experiments to investigate the mechanisms of discrimination of natural concepts, both in humans and in other animals. However, such stimulus sets are frequently difficult for either animals or humans to discriminate. Properties of artificial polymorphous stimulus sets that might explain this difficulty include the complexity of the individual stimuli, the unreliable reinforcement of individual positive features, attentional load, difficulties in discriminating some stimulus dimensions, memory load, and a lack of the correlation between features that characterizes natural concepts. An experiment using chickens as subjects and complex artificial visual stimulus sets investigated these hypotheses by training the birds in discriminations that were not polymorphous but did have some of the properties listed above. Discriminations that involved unreliable reinforcement or high attentional load were found to approach the difficulty of polymorphous concept discriminations, and these two factors together were sufficient to account for the entire difficulty. The usual kind of artificial polymorphous concept may not be a good model for natural concepts as they are perceived and discriminated by birds. A RULEX account of natural concept learning may be preferable.

A review of current economic theory and data is presented by focusing on economic self concept.

Research was conducted to study the trade-off between food finding and food stealing in the young oystercatchers, Haematopus ostralegus. Juvenile foraging behavior was compared with that of older birds to identify changes in juvenile decision taking from behavioral changes induced by the foraging environment. Additional data on time cost were also collected to evaluate the profitability of stealing a mussel rather than finding one on the mussel bed.

An economic-psychological examination of the concept of pride was conducted. This study investigated the role of pride in three economic contexts: in work, where pride may result in a preference for producing high-quality work; in social security benefits, where pride may reduce take-up; and in negotiations, where pride may generate an 'irrationally' difficult negotiating position. Pride is argued to be present in all cases since economic decisions are not made separately from one another but are interconnected by the selfhood of the decisionmakers. Pride can foster maladaptive decisions but can also generate long-term benefits.

INTRODUCTION Most books on work motivation stress that there is a big difference between activities that are externally motivated by rewards and activities that are intrinsically motivating, meaning that they [...]

A survey was conducted to study the psychological variables associated with consumer debt. The postal survey was done with the assistance of a public utility company. The questionnaires were sent to non-debtors, mild debtors and serious debtors. Non-debtors had more money management facilities and rated their money management abilities high. Psychological and behavioral variables affecting debt are related to the psychology of poverty.

A sample of undergraduate students is used in a study on the levels of debt and attitude towards debt. Findings show that students tend to be a low-income group, with high debts and high debt tolerance. Religion, age, number of credit cards used and tolerance towards debt are some variables significantly affecting the student group.

Four experiments where the subjects rated the utility of consumer goods were used to study predictions of microeconomic theory. The first experiment showed that marginal utility was dependent on the price and not on the frequency of consumption of the goods. Subjects independently rated total and marginal utility in the second experiment. Goods with higher demand elasticity were valued less in experiment three. There was a positive correlation between consumer's surplus and average value of goods in the fourth experiment.

In a first experiment, pigeons were trained to discriminate two pairs of simultaneously presented stimuli. A+ C- and B+ D-. Both pairs were successively and repeatedly presented in every session. After the birds learned the two discriminations, both tasks were synchronously reversed (i.e., A- C+ and B- D+) several times. When reversal performance had stabilized, test reversal sessions were run in which one discrimination (the 'leader' task, e.g., A+ C-) was presented for several trials before the second one (the 'trailer' task, e.g., B+ C-) was introduced. The animals acquired the trailing task somewhat faster than the leading task, suggesting that associations A [equivalence] B and C [equivalence] D that had built up between the stimuli forming the two discrimination pairs were supporting a reversal transfer. A second experiment showed that further reversal experience with a discrimination where the constituent stimuli were presented compounded (AB+CD- or AB-CD+) as well as singly, enhanced the transfer between leading and trailing tasks in subsequent test sessions. A third experiment showed that the same pigeons learned half reversals involving only one discrimination (for example by switching from A+ B-, C+ D- to A- B+, C+ D-) more slowly than full reversals involving both discriminations. These results support the hypothesis that pigeons can associate stimuli that have concordant reinforcement histories. When a reinforcement allocation change causes a change in responding to one stimulus of such an association, pigeons tend to generalize that response change to the other stimulus., Although the old dispute about whether or not conditioning leads to a strengthening of stimulus-stimulus or of stimulus-response connections has generally been resolved by conceding that it can do both, [...]

Researchers in economic psychology should revise their research methodology into economic socialization from an adult to a child-centered process. In particular, researchers have preoccupied themselves with how children perceive the economic realities of adults rather than how children respond to and manipulate their economic relationships. Insights into children's economics can be examined by their behavior in playground games such as marbles and by their swapping of things owned.

A survey was conducted to determine the relationship between consumer debt and various factors such as economic resources and need, social support and attitude. The strongest correlation was found between economic factors and indebtedness. However social and psychological factors were also significant. Serious debtors generally have lower incomes and more children, were more permissive about debts and tended to have conformist attitudes.

The acceptability of money as repayment for neighborly assistance is studied. Four hundred households in four different neighborhoods were surveyed and results show that money is not always acceptable in repaying neighborliness. Eighty-one percent of respondents said they would offer money in exchange for borrowed food, although 41% of this 81% believed their neighbor would not accept the money. On the other hand, only 9% said they would offer money for being loaned a tool, while 18% would offer money for assistance on a do-it-yourself job. Most respondents would rather offer to do their neighbors a favor, give the same help in the future or purchase a gift in exhange for neighbors' help. Analysis also showed that help recieved was determined by age, length of residence and the number of people in the area that respondents call by name.

A study by P.E. Lowther on the nest selection of the brown-headed cowbird, M. ater, is flawed because of the procedure in which the Poisson distribution was used to test the shotgun model of brood parasitism. Data from the study of shiny cowbirds', Molothrus bonariensis, brood parasitic use on the nests of house wrens were reexamined using truncated Poisson distribution to determine the feasibility of the shotgun model. Results showed that the model is valid and can be applied to the behavior of brown-headed cowbird, M. ater.

The two experiments that examined pigeonsE generalization to intermediate forms following training of concept discriminations are presented. In both experiments, pigeons learned the concept discrimination quickly and generalized with some decrement to novel instances of the categories.

Research on pigeons' directional movement discrimination indicates that experimental history of an object's movement against stationary discrimination fosters learning directional motion discrimination. This learning model is compared to one without previous movement/static discrimination, in which learning was poor.

Three experiments were conducted on pigeons to investigate categorization in relation to the impact of the dimension of movement on visual perception and visual discrimination. Six conclusions can be derived from the studies. Among them is the fact that pigeons can respond discriminately to categories of movement from scenes presented on videotape, that discriminations as trained are relatively difficult and discrimination is not enhanced by testing under extinction conditions.