Discrimination theory of rule-governed behavior

In rule-governed behavior, previously established elementary discriminations are combined in complex instructions and thus result in complex behavior. Discriminative combining and recombining of responses produce behavior with characteristics differing from those of behavior that is established through the effects of its direct consequences. For example, responding in instructed discrimination may be occasioned by discriminative stimuli that are temporally and situationally removed from the circumstances under which the discrimination is instructed. The present account illustrates properties of rule-governed behavior with examples from research in instructional control and imitation learning. Units of instructed behavior, circumstances controlling compliance with instructions, and rule-governed problem solving are considered.     

Phencyclidine discrimination in the pigeon using color tracking under second-order schedules

Pigeons were trained to track different key colors, depending on whether they had been injected with phencyclidine or saline prior to the session. A second-order schedule was used to generate large numbers of responses prior to the initial food delivery. The procedure offers several advantages over traditional procedures for studying drug discrimination.     

Stimulus control of the pigeon's ability to peck a moving target.

Two pigeons were trained to peck whichever of eight keys displayed a white field (SD). The other seven keys displayed a white "X" on a black background (S delta). Each peck to SD produced three-second access to grain, a three-second intertrial interval (ITI), and the next trial. Pecks to S delta produced a three-second timeout (TO) and the same trial. During later sessions the key displaying SD changed every t seconds (t = 3, 2, 1, .5, and .25 sec), requiring the birds to track the position of the SD. Pecks on a ninth key increased t. Several sessions employed novel stimuli to ascertain the controlling stimulus dimensions. Both birds made few errors acquiring the original discrimination. During the tracking sessions, both birds made few errors when t = .5 sec. Only one reliably lengthened t. Data from sessions with novel stimuli indicate that color and form were important aspects of SD and S delta respectively; movement contributed to the final performance.     

INTERTRIAL INTERVAL DURATION AND LEARNING IN AUTISTIC CHILDREN

This study investigated the influence of intertrial interval duration on the performance of autistic children during teaching situations. The children were taught under the same conditions existing in their regular programs, except that the length of time between trials was systematically manipulated. With both multiple baseline and repeated reversal designs, two lengths of intertrial interval were employed: short intervals with the S^D for any given trial presented approximately one second following the reinforcer for the previous trial versus long intervals with the S^D presented four or more seconds following the reinforcer for the previous trial. The results showed that: (1) the short intertrial intervals always produced higher levels of correct responding than the long intervals; and (2) there were improving trends in performance and rapid acquisition with the short intertrial intervals, in contrast to minimal or no change with the long intervals. The results are discussed in terms of utilizing information about child and task characteristics in terms of selecting optimal intervals. The data suggest that manipulations made between trials have a large influence on autistic children's learning.     

Temporal discrimination and a free-operant psychophysical procedure.

Pigeons were presented a series of keylight time periods (separated by blackouts) during which two response keys were lit, one by blue light and the other either by orange or green. Blue-key responses changed the color on the other key. Orange-key responses sometimes produced food during the first half of a time period; green-key responses sometimes produced food during the second half. In three experiments, the probability of a green-key response increased as a function of elapsed time. Experiment 1 compared performance when the duration of the keylight periods was varied across a wide range. Discrimination of performance was similar across the range of durations. Experiment 2 varied both relative reinforcement rate and the local reinforcement rate for orange-key and green-key responses. These manipulations produced changes in response bias but not discrimination sensitivity. Experiment 3 varied the local temporal placement of reinforcers within time periods and demonstrated that choice behavior was affected by differential reinforcement at different points during the time periods. The results were consistent with previous research on duration discrimination that used psychophysical trials procedures.     

Discrimination and differentiation of response number in stimulus directed pecking of pigeons.

In Experiment 1, autoshaping trials terminated with food only if pigeons emitted more than a target number of responses during a trial in one condition and fewer than a target number in another. The median number of responses per trial shifted in accordance wtih the requirements. The responding of yoked-control birds that received response-independent reinforcers did not vary with the response requirements. In Experiment 2, the number of responses in autoshaping trial became the discriminative stimulus for reinforcement in the second component of a chained schedule. In one condition, responding was reinforced only if the number of responses in the first component was above a target value; in the other condition, responding was reinforced only if the number was below the target value. The distribution of the first-component response numbers did not shift systematically between discrimination conditions, but response rates in the second component indicated that the number of responses in the autoshaping trial was a discriminable property behavior.     

Mozambican immigrants to South Africa: Their xenophobia and discrimination experiences

We explored Mozambican immigrants’ lived experiences of xenophobia and discrimination in South Africa. Informants were 15 Mozambican immigrants (female = 7, male = 8) living in an informal settlement in Zandspruit, Gauteng Province. They completed open-ended written narratives on xenophobic and discriminatory experiences. Following thematic analysis, we identified three themes to characterise the Mozambican immigrants’ experiences of xenophobia and discrimination: (i) abusive attitudes, (ii) ethnic discrimination, and (iii) scapegoating. The Mozambican immigrants’ experiences of xenophobia and discrimination are consistent with findings from the extant international literature on ingroup/outgroup social strife with real or perceived scarcity of resources.     

Constructions of social selves living with HIV/AIDS: A Jungian phenomenological study

This study explored sense of social well-being influences on self-identity and the stigma and discrimination among people living with HIV/AIDS (PLWHA). Informants were 15 PLWHA from a rural background in a South African community (female = 87%, age range = 26 to 64 years; and males = 13%, age range = 55 to 64 years). They completed semi-structured interviews on their lived experiences relating to a sense of social inclusion and belongingness. We thematically analysed the data, and interpreted the findings applying Jungian archetypes of the Self, Shadow, and Persona. Findings suggest PLWHA’s sense of a dominant Shadow to be a barrier to self-acceptance whereas a Persona (mask) was guided by a need to be socially acceptable. A positive sense of social well-being among PLWHA is important to their health and well-being.     

National disidentification and minority identity: A study among Muslims in Western Europe

Host national disidentification in which immigrants explicitly distance themselves from society is problematic for a cohesive national community and is likely to hamper immigrants’ successful host society integration. Among Sunni Muslim immigrants of Turkish origin living in Germany and the Netherlands we tested whether (a) an empirical distinction between national disidentification and identification can be made, (b) whether higher perceived group discrimination of Muslims (“reactive religiosity path”) and (c) stronger Muslim self-centrality (“intrinsic religiosity path”) are associated with stronger host national disidentification, to the extent that they are associated with a stronger commitment to religious identity content. Disidentification was found to be a separate construct and both the reactive religiosity path and the intrinsic religiosity path were found to be related to higher levels of disidentification, mediated by religious identity.