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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.

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.

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.

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.

Previous studies have shown that Eastern grey squirrels modify their behaviour while foraging to offset risks of social and predatory costs, but none have simultaneously compared whether such modifications are performed at a cost to foraging. The present study directly compares how grey squirrels respond to cues of these risks while foraging. We simulated social risk and predatory risk using acoustic playbacks of stimuli that grey squirrels might be exposed to at a foraging patch: calls of conspecifics, heterospecifics (competitor and non-competitor) and predators. We found that grey squirrels responded to predator, heterospecific competitor and conspecific playbacks by altering their foraging and vigilance behaviours. Foraging was most disrupted by increased vigilance when we played calls of predators. Squirrels’ response to calls of heterospecific competitors did not differ from their response to conspecific calls, and they resumed foraging more quickly after both compared to predator calls: whereas they showed little response to calls of non-competitor heterospecifics and a white noise control. We conclude that squirrels respond differentially to calls made by conspecifics, heterospecific competitors and predators, with the most pronounced response being to calls of predators. We suggest that squirrels may view conspecific and corvid vocalisations as cues of potential conflict while foraging, necessitating increased vigilance. [ABSTRACT FROM AUTHOR]

Pigeons were trained to discriminate photographs of cat faces from dog faces, using either high- or low-pass spatial frequency filtered stimuli. Each pigeon was trained with multiple exemplars of the categories, but only with either high-pass or low-pass filtered stimuli. Not all pigeons reached the discrimination criterion. Successful pigeons were exposed in probe trials to test stimuli: cat and dog faces that had been subjected to the opposite kind of filtering from their training stimuli; the unfiltered original stimuli from which their training stimuli had been derived; and new exemplars of the cat- and dog-face categories, with the same filtering as was used in training. There was no transfer of discrimination to the stimuli with the opposite filtering from those used in training. Discrimination transferred, with some decrement, to the original unfiltered stimuli and to new exemplars with the same type of filtering as used in training. These results provide further evidence that both high and low spatial frequency information can be sufficient for pigeons to make category discriminations, and that there is no clear advantage for high spatial frequency information. They also confirm that high-pass and low-pass spatial frequency filtering produce images that have effectively no information in common. This article is part of a Special Issue entitled: Tribute to Tom Zentall. [ABSTRACT FROM AUTHOR]

Abstract: How can animals learn the prey densities available in an environment that changes unpredictably from day to day, and how much effort should they devote to doing so, rather than exploiting what they already know? Using a two-armed bandit situation, we simulated several processes that might explain the trade-off between exploring and exploiting. They included an optimising model, dynamic backward sampling; a dynamic version of the matching law; the Rescorla–Wagner model; a neural network model; and ɛ-greedy and rule of thumb models derived from the study of reinforcement learning in artificial intelligence. Under conditions like those used in published studies of birds’ performance under two-armed bandit conditions, all models usually identified the more profitable source of reward, and did so more quickly when the reward probability differential was greater. Only the dynamic programming model switched from exploring to exploiting more quickly when available time in the situation was less. With sessions of equal length presented in blocks, a session-length effect was induced in some of the models by allowing motivational, but not memory, carry-over from one session to the next. The rule of thumb model was the most successful overall, though the neural network model also performed better than the remaining models. [Copyright &y& Elsevier]

Abstract: Economic theory and data are reviewed in the light of the concept of an economic self. In psychology, the self is in principle held to be a unified entity underlying all decisions, but in practice this unity is undermined by failures of transparency and complications of reflexivity. Current economic theory is found to be deficient in not recognising a self, but economic data confirm that the unity of the self is not absolute. A fuller account of the economic self will require a recognition of the role of human nature and emotions such as pride in forming economic tastes. [Copyright &y& Elsevier]

This review focuses on the success and survivorship of captive-born versus wild-caught carnivores used in reintroductions. Previous reviews have suggested that reintroduction projects using captive-born animals are less likely to be successful than projects translocating wild-caught animals. The purpose of this paper is to examine this statistically and investigate how captivity may affect the survival of reintroduced carnivores. We examined results published in previous reviews, and found evidence to support that reintroduction projects using wild-caught animals are significantly more likely to succeed than projects using captive-born animals. We further compiled our own review of 45 case studies in carnivore reintroduction projects (in 17 species across 5 families) to investigate survival rates rather than overall project ‘success’. We found that (1) wild-caught carnivores are significantly more likely to survive than captive-born carnivores in reintroductions; (2) that humans were the direct cause of death in over 50% of all fatalities and (3) that reintroduced captive-born carnivores are particularly susceptible to starvation, unsuccessful predator/competitor avoidance and disease. [Copyright &y& Elsevier]