Two multiple-schedule experiments with pigeons examined the effect of adding food reinforcement from an alternative source on the resistance of the reinforced response (target response) to the decremental effects of satiation and extinction. In Experiment 1, key pecks were reinforced by food in two components according to variable-interval schedules and, in some conditions, food was delivered according to variable-time schedules in one of the components. The rate of key pecking in a component was negatively related to the proportion of reinforcers from the alternative (variable-time) source. Resistance to satiation and extinction, in contrast, was positively related to the overall rate of reinforcement in the component. Experiment 2 was conceptually similar except that the alternative reinforcers were contingent on a specific concurrent response. Again, the rate of the target response varied as a function of its relative reinforcement, but its resistance to satiation and extinction varied directly with the overall rate of reinforcement in the component stimulus regardless of its relative reinforcement. Together the results of the two experiments suggest that the relative reinforcement of a response (the operant contingency) determines its rate, whereas the stimulus-reinforcement contingency (a Pavlovian contingency) determines its resistance to change.Key words: alternative reinforcement, response rate, resistance to change, concurrent schedules, multiple schedules, satiation, extinction, key peck, pigeon Experimental analysis has distinguished two aspects of operant behavior: the rate of a response and the resistance of that rate to reduction by procedures such as satiation and extinction. These two aspects of behavior are of interest because they vary in orderly ways as functions of rate of reinforcement (Catania & Reynolds, 1968;Nevin, 1974Nevin, , 1979Skinner, 1938Skinner, , 1950 and because of their relation to the theoretical concept of response strength. Although response rate has been taken as equivalent to response strength (Skinner, 1938(Skinner, , 1950 to be (Nevin, 1974(Nevin, , 1979Smith, 1974). Consequently, it is of some importance to examine the variables that influence resistance to change (Fath, Fields, Malott, & Grossett, 1983;Nevin, 1974Nevin, , 1979Nevin, , 1984Nevin, Mandell, & Yarensky, 1981;Nevin, Smith, & Roberts, 1987).The rate of a target response maintained by a given rate of reinforcement decreases when reinforcers are added concurrently from an alternative source. This decrease occurs both when reinforcers are added noncontingently (Rachlin & Baum, 1972) and when they are contingent on a different, concurrent response (Catania, 1963). Adding reinforcers from an alternative source may be viewed as degrading the operant contingency, in that the correlation between the occurrence of the target response and the reinforcer is thereby weakened. Thus, alternative reinforcement might reduce response rate by degrading the operant contingency.If a target response's rate and resistance to chan...

Both temporary and long-term sources of construct accessibility have been found to play an important role in person perception and memory. Yet the two effects heretofore have been studied in isolation from each other. We examined the joint influence of long-and short-term sources of accessibility on impression formation. Subjects with or without a long-term, chronically accessible construct for either kindness or shyness were exposed subliminally to either 0 or 80 trait-related words in a first task. Next, subjects read a behavioral description that was ambiguously relevant to the primed trait dimension, and they then rated the target on several trait scales. For both the kind and the shy trait conditions, both chronic accessibility and subliminal priming reliably and independently increased the extremity of the impression ratings. The results supported a model in which long-and short-term sources of accessibility combine additively to increase the likelihood of the construct's use. Moreover; the subliminal priming effect appeared to be a quite general and pervasive phenomenon, insofar as it occurred for both an evaluatively positive and an evaluatively neutral trait dimension and for subjects without as well as with a chronically accessible construct for the primes. Implications of these findings for the nature of construct accessibility and the generality of automatic influences on social perception are discussed.A mainstream of social cognition research has focused on the nature of the mechanism by which people interpret social stimuli. In their seminal works, Kelly (1955) andBruner (1957) argued that people develop mental constructs, or categories, out of the necessity to cope effectively and adaptively with an overabundance of complex information. An important difference between Kelly's and Bruner's conceptualizations of social categories is the duration of category influences with which they mainly were concerned. Bruner (1957) focused on temporary differences in the likelihood that a specific category would be used: what he termed its accessibility. Categories that were used recently, or that were relevant to current goals or needs, were said to be more likely than others to "capture" an input as an instance of the construct. Given the ambiguity and multiple implications of most social information, Bruner argued, an accessible category may well be used to interpret behaviors or events that are actually more relevant for other, but less accessible, categories (see also Bruner, 1951;Postman, 1951).

We are grateful to Gordon Logan, Tory Higgins, and two anonymous reviewers for their extensive and valuable comments on an earlier version of this article. We also extend our appreciation to Concepcion Jusino, Jr., and Cathy LaFata for serving as the experimenters for the study.

Mutual influencing processes are assumed to be the basic building blocks in establishing parent-child bonding and in influencing cognitive and language behavior. A study by Jasnow and Feldstein (1986) revealed that, within the temporal domain of speech, preverbal (9-month-old) infants and their mothers exhibit a pattern of mutual influence (attunement) in their average durations of switching pauses. The general purpose of this research was to extend those findings to children with higher verbal functioning. In addition, parent and child genders, nature of the interaction, and specific aspects of parents' personalities, expressiveness, and instrumentality were considered. Each parent interacted with their 4- or 5-year-old son or daughter in each of two conversations--unstructured (social conversation) and structured (task activity). Conversations were processed by an automated computer system yielding objective measure of turns, vocalizations, pauses, and switching-pause durations. To examine interspeaker influence of attunement of temporal speech patterns, "influence coefficients" were computer for each speaker on a "turn-by-turn" basis using time series regression. Analysis of these coefficients revealed that: (1) Mutual influence is most evident with switching-pause duration. (2) Structure in the conversation (as defined by the task or parental instrumentality) seems to facilitate attunement for vocalization and switching pause duration. (3) Attunement with girls seems to occur equally well with both parents, while boys exhibit a style of temporal patterning influence which suggests greater identification with the father. (4) Expressiveness seems to facilitate attunement to the child's switching-pause duration.