A study of some conditions relating to the retarded adult's stereotyped responding in a binary-choice task

This study was a longitudinal one that examined the effects of certain conditions on alternation and perseveration in a binary-choice task. The conditions manipulated included: (1) lapse of time (stability of the pattern), (2) stimulus dissimilarity, (3) spatial location of the two alternatives, (4) time-out (time away from the task), (5) delay between responses, and (6) differential reinforcement of the two choices. Eight mentally retarded adults, identified as “pure” alternaters or perseveraters, served as subjects. Perseveration was “disrupted” only by differential reinforcement. Alternation was affected by all experimental manipulations with the exception of stimulus dissimilarity.     

Bobo clown aggression in childhood: Environment,not genes

We videotaped 216 twin children (average age: 7.6 years) hitting a 5-ft “Bobo clown”. Three behaviors in the Bobo clown situation showed adequate response characteristics, rater reliability, and test-retest reliability: number of hits, intensity of hits, and number of quadrants (into which the Bobo clown was hit). In terms of two “anchor” variables, height and weight, the twin correlations were representative of other studies in suggesting substantial hereditary influence. However, twin analyses of the three behavioral ratings during the Bobo clown session yielded no evidence of hereditary influence. Moreover, the results provided evidence of substantial environmental influence of the “between-family” variety. In other words, the family environment is the major source of individual differences for these measures.     

A parent-offspring adoption study of cognitive abilities in early childhood

Do cognitive abilities in early childhood relate genetically and/or environmentally to isomorphic abilities in adulthood? Are specific cognitive abilities diffentiated in early childhood in terms of their prediction of adult cognitive abilities? The present study, the first behavioral genetic analysis of specific cognitive abilities in early childhood, explored these questions using parent-offspring data for 186 adopted children and 151 nonadopted children tested in the longitudinal Colorado Adoption Project at 3 years of age and 162 adopted children and 138 nonadopted children tested at 4 years. The children's Stanford-Binet IQ and scores for four specific cognitive abilities (verbal, spatial, perceptual speed, and memory) were correlated with corresponding measures for their parents—the biological and adoptive parents of the adopted children and the natural parents of the nonadopted children. Significant correlations were found between biological mothers' IQ and the IQ of their adopted away offspring at 3 and 4 years of age, suggesting genetic influence for IQ. However, specific cognitive abilities yielded no significant correlations between biological mothers and their adopted-away offspring. These results suggest that substantial genetic continuity exists for IQ from early childhood to adulthood, but not for specific cognitive abilities.     

The ambiguous-cue problem: The effects of reduced similarity between trials and the schedule of reinforcement

In a series of seven experiments pigeons were trained on the two-choice ambiguous-cue problem that contains PA and NA trials. On PA trials choice of P (the positive stimulus) was reinforced and choice of A (the so-called ambiguous stimulus) was not reinforced; on NA trials choice of A was reinforced and choice of N (the negative stimulus) was not reinforced. When the two types of trials were distinguished by only the presence of P or N and each trial was terminated by one response, subjects quickly attained high levels of performance on NA trials but showed only chance levels of performance on PA trials. PA performance was markedly improved when a variety of additional stimuli distinguished the two types of trials and when a variety of schedules of intermittent reinforcement were employed; these manipulations had little effect on NA performance.     

Some variables affecting children's compliance with instructions

Children were given instructions to perform different tasks. Compliance was studied as a function of several variables: the prevailing pattern of reinforcement for different instructions, the availability of a competing reinforced activity, and the similarity among tasks. Rate of compliance tended to decrease when the probability of reinforcement for compliance decreased, or when a competing reinforced activity was available. Differential reinforcement over the tasks did not always produce discriminative responding even under favorable conditions. Novel instructions obtained compliance at the same rate as that for frequently repeated instructions, independent of the novel instruction's past or present reinforcement history. Greater discrimination in responding was found when tasks were less similar. Results imply that sets of instructions may form a response class, with characteristics similar to those found in studies of generalized imitation.     

A developmental and cross-cultural study of the influences of rule structure and problem composition on the learning of conceptual classifications

Five experiments were conducted permitting direct comparisons in the way Ss of different ages and cultures solved conceptual problems. One group of problems (Traditional) could be solved using a reference rule of conjunction or disjunction. Another group of problems (Intradimensional) could be solved either by one of the reference rules, or by a structurally simpler rule. Analysis of American performance confirmed that older Ss not only solved using the simpler rule more often than younger Ss, but when they did so they solved faster. For both American age groups, solution using the simpler rule led to no difference in performance between conjunctive and disjunctive Intradimensional problems. Conjunction proved easier than disjunction only for the Traditional problems. Unlike Americans, the Kpelle of Liberia did not solve using the simpler rule, and found conjunction easier than disjunction for both Traditional and Intradimensional problems. When a memory aid was provided the Kpelle showed a pattern of performance exactly like Americans.     

Heart rate conditioning in the newborn infant

In an attempt to condition heart rate in newborns, 21 infants were assigned to Conditioning, Random Control, and Backward Conditioning Groups. During training trials, the Conditioning Group received an eight-second tone (CS), a six-second ISI, and a ten-second presentation of glucose via nipple (UCS) that overlapped the last two seconds of tone. The Random Control Group received tones at the same intertrial intervals as the Conditioning Group, but glucose varied randomly. The Backward Conditioning Group received glucose during the ten seconds immediately preceding tone onset. The response to both CS and UCS during base trials was HR acceleration. The response to tone habituated in all groups, but the acceleration to glucose was maintained throughout conditioning. Although no conditioned response to the tone developed over trials, a large HR deceleration appeared during extinction to the absence of the UCS in the Conditioning Group only. This deceleration was interpreted as an orienting response to the absence of an expected event.     

Stimulus control and delayed reinforcement

Pigeons were tested for generalization along the line-orientation dimension, after being trained on various two-component multiple schedules. The first component contained either a variable-interval 1-min schedule of immediate reinforcement or an extinction schedule and was associated with a plain white key (S1). The second component contained a variable-interval 1-min schedule of delayed reinforcement and was associated with a black line on a white background (S2). The major results showed that (a) decremental gradients were obtained around the stimulus associated with the delayed reinforcement component when S1 was associated with extinction, but that incremental gradients were obtained when S1 was associated with immediate reinforcement, (b) the subjects' pretraining did not affect the generalization gradients if sufficient training on the terminal multiple schedule was provided, and (c) changing the S1 schedule from immediate reinforcement to extinction produced behavioral contrast if reinforcement was delayed for 10 sec during S2, but not if it was delayed for 20 sec.     

The role of inference in children's comprehension and memory for sentences

In a series of studies, young children often failed to construct and remember inferred relationships which they were capable of understanding. A cued recall procedure was employed to assess the relative effectiveness of implicit and explicit word prompts for sentence memory. The implicit cues were much less effective than the explicit cues for 6–7 yr old children while the cue types did not differ for 11–12 yr olds. Instructions to imitate the actions described by the sentences eliminated the memory difference for the young children. Developmental improvement in spontaneous inferential operations and intentional plans to remember are mechanisms which appear to yield an elaborated memory representation and greater access routes through indirect and implied relationships.     

Children's avoidance responses to three probabilities of threatened consequences

Children's avoidance responses were conditioned and then extinguished in a laboratory analog of a social threat situation. Aversive events (story interruptions) were programmed to follow either 100% (group E100) of the signals (threats), 60% (group E60) of the signals, or 20% (group E20) of the signals during acquisition. The subjects could avoid the signal and/or the aversive event by responding with lever presses above criterion level. Results indicated that groups E100 and E60 were generally not different from each other but avoided significantly more interruption and signals and responded at a higher rate than group E20. Groups E100 and E60 both shifted their responding from approximately equivalent probabilities of signal and interruption avoidance to relatively greater avoidance of interruptions during acquisition, and then shifted back to equivalent probabilities of signal and interruption avoidance during extinction. Results were discussed in terms of the function of threats as discriminative stimuli.     

Relational responses in tests of transposition with Rhesus monkeys

Three adult Rhesus monkeys (Macaca mulatta), one with nonrelated discrimination learning experience and two experimentally naive, were trained to discriminate between two simultaneously presented stimuli differing only in height. After exceeding the learning criteria on a VR 4 reinforcement schedule and considerable overtraining, subjects were tested for transposition. Both upward and downward and near and far tests were administered to determine the effects of distance from the original training pair on the amount of transposition. In these tests, each of the 24 stimulus pairs contained one or more novel stimuli. Training trials were interpolated to avoid extinction effects and measures were taken to avoid motivational deficits or differential rewards during testing. All three subjects responded relationally at far as well as near distances from the original training pair. Stimulus generalization, on the basis of increments of association, was found to be an inferior explanation for these data. Slight decrements on far tests can be better explained in terms of the learning-performance distinction.     

Teaching awareness of strategic behavior in combination with strategy training: Effects on children's memory performance

The present study examined the effectiveness of two components (rehearsal training and strategy awareness) of an instructional package designed to train the developmentally young in the use of mature information processing techniques. Two groups of children of equivalent developmental age (MA = 8), one mildly retarded and the other of average intelligence, participated. Rehearsal training was effective in improving recall scores on the training task; however, neither rehearsal training, memory awareness, nor their combination significantly altered memory performance on the generalization tasks. There was evidence, however, that the combination of rehearsal training and strategy awareness did increase the likelihood of strategy transfer on the generalization task (recognition) which most closely resembled the training task. Post-task questioning revealed that instructions concerning memory awareness did improve subjects ability to verbalize appropriate strategic behavior; however, these improvements were not consistently translated into either actual use of a rehearsal strategy or improved performance. Discussion centered on the implications of these results and on the need for increased research on the metamnemonic skills involved in strategy generalization.     

Reinforced practice and reduction of different kinds of fears in adults and children

The purpose of this study was to determine whether or not fears with different origins, course and chronicity could be reduced by a common treatment program. A number of therapeutic procedures that had been experimentally demonstrated to be individually important in prior behavior modification studies with neurotic disorders were combined into a single therapeutic program called ‘reinforced practice.’ The combined elements were: graduated and repeated practice in approaching actual phobic stimuli: reinforcement for gains in performance; feedback of measurable progress; and instructions designed to arouse expectations of gradual success. In each of four experiments involving four different fears, namely fear of heights, snakes and electric shock in adults, and fear of darkness in young children, Ss who expeienced the ‘reinforced practice’ procedure improved their performance by a significant and substantial margin as compared to untreated control Ss. These results suggest that regardless of different etiologies, regardless of whether or not the fears are ‘rational’ or ‘irrational,’ and regardless of whether or not the fears are transitory or long lasting, the same treatment procedure can be equally effective in reducing escape-avoidance behavior.     

Categorical and spatial modes of representation in young children's recall

Preschool children aged 4 and 6 were asked to recall a set of line drawings under two conditions: pictures blocked in category groups, and pictures blocked in noncategory groups. For 4-year-olds, the blocking condition made no difference in the structure of their recall; but for the 6-year-olds, the category blocking served as a support for category clustering of their recall lists. No purely spatial clustering appeared at either age. It was concluded that 6-year-olds' use of classes is closely linked to concrete spatial arrangement of objects.