Abstract: Attempted to determine whether the sanctioning behavior of naive trainers is consistent with principles of behavior modification, that is, responsive to a trainee's performance alone, or whether it is influenced by variables other than performance. 2 variables which may affect the administration of rewards and punishments are the perceived competence of the trainee and difficulty of the task. These 2 variables were manipulated in a 2 * 2 factorial design with easy and difficult tasks and competent and noncompetent trainees. The trainers were responsible for administering rewards and punishments to trainees while teaching them a concept task; use of a confederate enabled identical trainee performance for all conditions. The data indicate that extraperformance variables do affect the reinforcing behavior of naive trainers as predicted by attribution theory. The results provide behavioral confirmation for predictions from the theory which has been primarily tested using perceptual judgmental data. (PsycINFO Database Record (c) 2006 APA, all rights reserved)

Abstract: This paper presents an antithesis to the view that gregarious behaviour is evolved through benefits to the population or species. Following Galton (1871) and Williams (1964) gregarious behaviour is considered as a form of cover-seeking in which each animal tries to reduce its chance of being caught by a predator.
It is easy to see how pruning of marginal individuals can maintain centripetal instincts in already gregarious species; some evidence that marginal pruning actually occurs is summarized. Besides this, simply defined models are used to show that even in non-gregarious species selection is likely to favour individuals who stay close to others.
Although not universal or unipotent, cover-seeking is a widespread and important element in animal aggregation, as the literature shows. Neglect of the idea has probably followed from a general disbelief that evolution can be dysgenic for a species. Nevertheless, selection theory provides no support for such disbelief in the case of species with outbreeding or unsubdivided populations.
The model for two dimensions involves a complex problem in geometrical probability which has relevance also in metallurgy and communication science. Some empirical data on this, gathered from random number plots, is presented as of possible heuristic value.