Concurrent schedules: Maximization versus reinforcement of changeover behaviour

Pigeons responded on concurrent variable-interval 180-sec variable-interval 36-sec schedules during Conditions 1 and 3 of Experiment 1. Condition 2 arranged variable-interval 60-sec schedules for both response alternatives. The schedule assigned to the alternative that was associated with the variable-interval 36-sec schedule in Conditions 1 and 3 operated only when the subject responded on that alternative. The proportion of time spent responding on the alternative with the conventional variable-interval 60-sec schedule increased during Condition 2, but exclusive choice of that alternative did not develop. This result is inconsistent with maximization of the overall reinforcement rate and with maximization of the momentary probability of reinforcement (momentary maximizing). Increasing time proportions were also found in Experiment 2, which arranged similar conditions, except that reinforcement was provided on a variable-time basis. The time proportions were close to the momentary maximizing prediction in Experiment 2. The results of both experiments can be explained if it is assumed that time allocation is controlled by delayed reinforcement of changeovers between alternatives.     

The descent of cognitive development

A constructivist theory of the evolution of cognitive development is proposed. Seven propositions are posed plus supporting evidence. Constructing fundamental physical and logicomathematical conceptual universals underlies the development of cognition in primate phylogeny, ontogeny and history. Nevertheless, diverging onset and offset ages, velocity, extent, sequencing and organization mark the evolution of cognitive development in primate phylogeny. Thus, the evolution is heterochronic, not simply recapitulatory. Converging origins followed by diverging development of primates' conceptual constructions insures species‐specific cognitive specializations. Some specializations (e.g. recursive classifying) evolved in great ape development but not in monkey development; while others (e.g. hierarchically integrated classifying) evolved in human development only. Human enculturation and language (symbolic) rearing fosters quantitative but not qualitative progress in most of chimpanzees’ developing cognition. Heterochronic evolution provided humans with the widest and most synchronic ontogenetic window of opportunity for progressive cognitive development. The descendant cognitive development – humans’ precocial, integrated and extended intellectual constructions – bridges the evolution and history of ideas.     

FISH 3: A microworld for studying social dilemmas and resource management

A Java-based microworld environment for studying resource management is described. FISH 3 may be used in research or the classroom to investigate commons dilemmas and resource dilemmas. The program uses ocean fishing as its metaphor; participants (“fishers”) experience the metaphor through both graphics (“fish” may be seen in an ocean) and text (e.g., resource replenishment is translated as “spawning”). In either stand-alone or networked modes, either with all human fishers or a mixture of human and computer fishers, 15 parameters such as the number of resource units (fish), participants (fishers), and trials (seasons), payoff values, the rate and period of resource regeneration (spawning), harvesting greed by computer fishers, awareness of other harvesters’ actions, uncertainty in the amount of the resource, operating costs, and whether the resource is visible to harvesters may be varied.     

Über die Empfindlichkeit für Gewichtsunterschiede bei abnehmender Reizstärke

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