In this reprint of a seminal article, once considered quite controversial, the authors discuss their radical claim that rats laugh. Even more provocative, the authors found that this rat-joy sound, especially evident during play, could be amplified dramatically by what they formally call heterospecific (cross-species) handplay (tickling). The…

Psychology texts often cite the work of Marian and Keller Breland and their business, Animal Behavior Enterprises (ABE), to demonstrate operant conditioning and the "misbehavior of organisms" from an evolutionary perspective. Now available on the Internet at the official IQ Zoo website (http://www3.uca.edu/iqzoo/), the artifacts of ABE's work, in…

This is a set of animal behavior investigations in which students will practice scientific inquiry as they observe crayfish, ask questions, and discuss territoriality, social interactions, and other behaviors. In doing this, they hone their skills of observation, learn to record and analyze data, control for variables, write hypotheses, make…

The effect of force requirements on response effort was examined using inbred C57BL/6J mice trained to press a disk with their snout. Lateral peak forces greater than 2 g were defined as responses (i.e., all responses above the measurement threshold). Different, higher force requirements were used to define criterion responses (a subclass of all…

A long delay inserted between conditioning and test phases of a 3-stage Latent Inhibition (LI) procedure produces differential effects on LI depending on the delay context. Thus, enhanced LI has been obtained when the delay is spent in a context that is different from the remaining experimental contexts, but not when it is the same. The present…

Mice communicate through visual, vocal, and olfactory cues that influence innate, nonassociative behavior. We here report that exposure to a recently fear-conditioned familiar mouse impairs acquisition of conditioned fear and facilitates fear extinction, effects mimicked by both an olfactory chemosignal emitted by a recently fear-conditioned…

Operant conditioning with "Betta splendens" ("Bettas") has been investigated extensively using males of the species. Ethological studies of female "Bettas" have revealed aggressive interactions that qualitatively parallel those between male "Bettas". Given these similarities, four experiments were conducted with female "Bettas" to examine the…

Stress is a biologically significant social-environmental factor that plays a pervasive role in influencing human and animal behaviors. While stress effects on various types of memory are well characterized, its effects on other cognitive functions are relatively unknown. Here, we investigated the effects of acute, uncontrollable stress on…

This experiment compared descriptions of concurrent choice by the stay/switch model, which says choice is a function of the reinforcers obtained for staying at and for switching from each alternative, and the generalized matching law, which says choice is a function of the total reinforcers obtained at each alternative. For the stay/switch model…

Food-deprived rats in Experiment 1 responded to one of two tandem schedules that were, with equal probability, associated with a sample lever. The tandem schedules' initial links were different random-interval schedules. Their values were adjusted to approximate equality in time to completing each tandem schedule's response requirements. The…

In the last decades, researchers have proposed a large number of theoretical models of timing. These models make different assumptions concerning how animals learn to time events and how such learning is represented in memory. However, few studies have examined these different assumptions either empirically or conceptually. For knowledge to…

Most mammals play, but they do so in a dangerous world. The dynamic relationship between the stresses created by their world and the activity of play helps to explain the evolution of play in mammals, as the author demonstrates in evidence garnered from experiments that introduce elements of fear to rats at play. The author describes the resulting…

This article presents an analysis of the longitudinal consequences of out-of-school science learning with a conceptual framework that connects the intentions of youth to their participation in science. The focus is on one girl's science activities in her home and hobby pursuits from fourth to seventh grade to create an empirical account of how…

arrow]US associations also survived The memories of the unconditioned stimulus (US) and its absence (No US), symbolized as S[superscript R] and S[superscript N], respectively, may be retrieved on US or No US trials giving rise to four types of associations, S[superscript R][right arrow]US, S[superscript R][right arrow]No US, S[superscript N][right…

In many nonhuman species of vertebrates, females are attracted to red on male conspecifics. Red is also a signal of male status in many nonhuman vertebrate species, and females show a mating preference for high-status males. These red-attraction and red-status links have been found even when red is displayed on males artificially. In the present…