Effects of schedule and magnitude of reinforcement under conditions of thirst motivation

In contrast to a recent finding (Macdonald, G. E., & De Toledo, L. Learning and Motivation, 1974, 5, 288–298.) the results of three experiments investigating various partial reinforcement (PRF) manipulations under conditions of thirst motivation demonstrated strong similarity to analogous manipulations involving food reward. Specifically, for animals receiving water reinforcement, PRF was shown to generate greater resistance to extinction than continuous reinforcement (Expt 1 & 3), the schedule of reinforcement was shown to interact with level of acquisition (Expt 1 and 2), and the magnitude of the partial reinforcement extinction effect was shown to be a function of reward magnitude (Expt 3). These results provide strong evidence that mechanisms which operate in partial reinforcement situations are highly similar, regardless of the type of appetitive reinforcement.     

An index of bewilderment

Stuart F. Spicker (ed.). The Philosophy of the Body: Rejections of Cartesian Dualism. Chicago, Illinois: Quadrangle Books, 1970. Pp. viii, 367. Not indexed. $2.95 (paper).     

Kotahitanga and koinonia in shalom as the objective of the mission of God

Evangelical theology and the missions that flowed from it was born in an era of high colonialism, shaped by enlightenment dualism and scientific method, under the influence of industrialization. As evangelical Christianity’s centre of gravity shifted south, global North dominance over its theology and missiology persisted, translated into new tongues. This paper, sensing a tipping point in evangelical thought as we emerge out of global pandemic disruption, proposes an alternative framing of church and missions from the collectivist perspective shared by those less affected by the influence of Western industrialization and individualism. It proposes that both the means and the objective of the mission of God should be common unity in-Christ. It shifts focus from the Great Commission to the Great Commitment, which emphasizes being one and holding fast to that unity for the joy that awaits those who persevere in mutuality. Along the way, the demonstration of whole-of-life covenantal community in-Christ serves as our witness to the world, which provides those of us in-Christ with an opportunity to explain the hope that we have and invite others to join us in the experience of God’s shalom goodness.     

Social preference in rats

Rats were given repeated choices between social and nonsocial outcomes, and between familiar and unfamiliar social outcomes. Lever presses on either of 2 levers in the middle chamber of a 3-chamber apparatus opened a door adjacent to the lever, permitting 45-s access to social interaction with the rat in the chosen side chamber. In Experiment 1, rats preferred (a) social over nonsocial options, choosing their cagemate rat over an empty chamber, and (b) an unfamiliar over a familiar rat, choosing a non-cagemate over their cagemate. These findings were replicated in Experiment 2 with 2 different non-cagemate rats. Rats preferred both non-cagemate rats to a similar degree when pitted against their cagemate, but were indifferent when the 2 non-cagemates were pitted against each other. Similar preference for social over nonsocial and non-cagemate over cagemate was seen in Experiment 3, with new non-cagemate rats introduced after every third session. Response rates (for both cagemate and non-cagemate rats) were elevated under conditions of nonsocial (isolated) housing compared to conditions of social (paired) housing, demonstrating a social deprivation effect. Together, the experiments contribute to an experimental analysis of social preference within a social reinforcement framework, drawing on methods with proven efficacy in the analysis of reinforcement more generally.