We studied economic choice behavior in capuchin monkeys by offering them to choose between two different foods available in variable amounts. When monkeys selected between familiar foods, their choice patterns were well-described in terms of relative value of the two foods. A leading view in economics and biology is that such behavior results from…

Combined activation of dopamine D1- and NMDA-glutamate receptors in the nucleus accumbens has been strongly implicated in instrumental learning, the process in which an individual learns that a specific action has a wanted outcome. To assess dopaminergic activity, we presented rats with two sessions (30 trials each) of a one-lever appetitive…

All animals must make choices regarding what foods to eat, where to eat, and how much time to spend feeding. Optimal foraging theory explains these behaviors in terms of costs and benefits. This laboratory exercise focuses on optimal foraging theory by investigating the winter feeding behavior of birds on the goldenrod gall fly by comparing…

The experiments reported here describe the relationships between the reflex-modulating effects of compounded stimuli and the effects of these stimuli when they act in isolation. (Author)

While incentive contrast has been reliably demonstrated in single-response situations, tests for contrast-of-choice behavior have invariably failed to obtain the effect. Three experiments were reported that eliminated features of prior methodology which can mask the effect. (Editor/RK)

This document consists of two separate papers. The first paper, "A Balanced Marine Aquarium" (Barbara Jayne Palko), discusses various aspects of a balanced marine aquarium. Information provided includes the basic and optional equipment needed to construct a balanced aquarium, preparations for setting up the aquarium, preparing the…

The present research evaluated the refractorylike response decrement, as found in habituation of auditory evoked peripheral vasoconstriction in rabbits, to determine whether or not it represents a short-term habituation process distinct from effector fatigue or sensory adaptation. (Editor)

This field guide is designed to permit observers to identify the cetaceans (whales, dolphins, and porpoises) they see in western North Atlantic, including the Caribbean Sea, the Gulf of Mexico, and the coastal waters of the United States and Canada. The animals described are not grouped by scientific relationships but by similarities in appearance…

This study investigated the effects of a short period of severe protein malnutrition on subsequent growth and development in the squirrel monkey. A total of 12 newborn monkeys were fed a low protein diet from 2 to 8 weeks of age then rehabilitated by returning them to the 13 percent protein diet of the control group. Minimum amount of protein…

This ancient Cherokee story details an encounter the Indians had with a strange beast after they misused nature thereby learning to respect the Creator. (RTS)

Using rats and pigeons as subjects, the effects of varying amounts of reinforcement on the rate and temporal patterns of interim and terminal behaviors engendered by periodic feeding schedules were assessed in three experiments. (Author/KC)

Five experiments investigated the differential effects of shock punishment on nonconsummatory licking (dry licking) and lever pressing. Results support a motivationally based theory of punishment involving the role of incentive stimuli associated with the particular responses studied. (Editor/RK)

There are some important similarities between biological and societal evolution, but these similarities should not blind the enormous differences between them. Each system must be analyzed on its own merits and according to its own peculiar properties and principles. (Author/AM)

There is no clearly defined, universally accepted evolutionary theory that social anthropologists must accept. There has been great progress in the understanding of genetic mechanisms, but there are still major controversies. The most fundamental problem comes from postulating genes to account for behaviors. (Author/AM)

A review of play in nonhuman animals indicates that play increases with phylogenetic status, is important for mature social development in more advanced species, reflects intentional activity, and is essential for the development of tool-using strategies. (Author)