Second-order schedules of token reinforcement with pigeons: effects of fixed- and variable-ratio exchange schedules

Pigeons' key pecks produced food under second-order schedules of token reinforcement, with light-emitting diodes serving as token reinforcers. In Experiment 1, tokens were earned according to a fixed-ratio 50 schedule and were exchanged for food according to either fixed-ratio or variable-ratio exchange schedules, with schedule type varied across conditions. In Experiment 2, schedule type was varied within sessions using a multiple schedule. In one component, tokens were earned according to a fixed-ratio 50 schedule and exchanged according to a variable-ratio schedule. In the other component, tokens were earned according to a variable-ratio 50 schedule and exchanged according to a fixed-ratio schedule. In both experiments, the number of responses per exchange was varied parametrically across conditions, ranging from 50 to 400 responses. Response rates decreased systematically with increases in the fixed-ratio exchange schedules, but were much less affected by changes in the variable-ratio exchange schedules. Response rates were consistently higher under variable-ratio exchange schedules than tinder comparable fixed-ratio exchange schedules, especially at higher exchange ratios. These response-rate differences were due both to greater pre-ratio pausing and to lower local rates tinder the fixed-ratio exchange schedules. Local response rates increased with proximity to food under the higher fixed-ratio exchange schedules, indicative of discriminative control by the tokens.     

Civic religion in England: Traditions and transformations

As the religious diversity of English towns and cities has grown over the past thirty years due to the establishment in some places of sizeable communities of Hindus, Muslims and Sikhs, as well as other faiths, there have been important changes to local public religion. Traditional civic ceremonies, such as Remembrance Sunday, as well as new forms of civic celebration and commemoration, are now increasingly taking account of the diversity of faiths represented in Britain. This paper examines the consequences of religious diversity for English civic religion by looking at some of the traditions of civic ceremonies in England and at the way in which they have been transformed by the changing religious landscape of towns and cities. The paper also explores some of the dilemmas and questions that have emerged both for the Church of England as well as for the other faith communities when it comes to the design and delivery of civic ceremonies.     

Covert discrimination against gay men by U.S. college students.

This study examined the use of sexual orientation as a meaningful social category and the consequences of using this category. The sample consisted of 260 U.S. college students who viewed a video and completed a 29-item scale (L. L. Thompson & J. Crocker, 1990) and the 7-item Homophobia Scale (R. A. Bouton et al., 1987). Results showed that participants' adjective ratings of targets favored gay men. Participants did not exhibit greater bias toward gay men when provided with justification. However, there was a pattern of bias in which participants showed favoritism toward heterosexual male targets when provided with no justification for bias.     

Mathematical engineering and mathematical change 1

In this paper, I introduce and examine the notion of “mathematical engineering” and its impact on mathematical change. Mathematical engineering is an important part of contemporary mathematics and it roughly consists of the “construction” and development of various machines, probes and instruments used in numerous mathematical fields. As an example of such constructions, I briefly present the basic steps and properties of homology theory. I then try to show that this aspect of contemporary mathematics has important consequences on our conception of mathematical knowledge, in particular mathematical growth.     

Infants’ coding of location in continuous space

The ability to code location in continuous space is fundamental to spatial behavior. Existing evidence indicates a robust ability for such coding by 12 months, but systematic evidence on earlier origins is lacking. A series of studies investigated 5-month-olds’ ability to code the location of an object hidden in a sandbox, using a looking-time paradigm. In Experiment 1, after familiarization with a hiding-and-finding sequence at one location, infants looked longer at an object being disclosed from a location 12 inches (30 cm) away than at an object emerging from the hiding location, showing they were able to code location in continuous space. In Experiment 2, infants reacted with greater looking when objects emerged from locations 8 inches (20 cm) away from the hiding location, showing that location coding was more finely grained than could be inferred based on the first study. In Experiment 3, infants were familiarized with an object shown in hiding-and-finding sequences at two different locations. Infants looked longer at objects emerging 12 inches (30 cm) away from the most recent hiding location than to emergence from the other location, showing that infants could code location even when events had previously occurred at each location. In Experiment 4, after familiarization with two objects with different shapes, colors, and sounding characteristics, shown in hiding-and-finding sequences in two locations, infants reacted to location violations as they had in Experiment 3. However, they did not react to object violations, that is, events in which the wrong object emerged from a hiding location. Experiment 5 also found no effect of object violation, even when the infants initially saw the two objects side by side. Spatiotemporal characteristics may play a more central role in early object individuation than they do later, although further study is required.