Category typicality effects in children's memory performance: Qualitative and quantitative differences in the processing of category information

Kindergarten, third, and sixth graders (6, 9, and 12 years of age, respectively) received a cue-at-input/cue-at-output recall task, using category typical and atypical items that were based on either (1) children's conceptions of item typicality, or (2) adults' conceptions of item typicality. At each grade level, recall was greater with the child-defined lists than with the adult-defined lists, and typical items were recalled to a greater extent than atypical items. Further analyses items were recalled to a greater extent than atypical items. Further analyses revealed that the recall of typical items varied as a function of children's typicality ratings of items, and that the “typicality effect” in the adult-norm condition was due primarily to the childrennot realizing that many of the atypical items were appropriate category exemplars. In contrast, typicality effects in the child-norm condition were attributed to qualitative differences in the judged “goodness of example” of the typical and atypical items. The results were discussed in terms of the appropriateness of typicality as a dimension of children's natural language concepts, the role of age differences in knowledge base in affecting performance on a cognitive task, and of the importance of using child-generated norms in studies of children's processing of category information.     

Developmental trends in children’s typicality judgments

Category typicality norms from 12 natural language categories are presented for kindergarten, third-grade, sixth-grade, and college students. Subjects first selected examples of familiar word concepts and rated them on a 3-point scale in terms of category typicality. Age differences in the percentage of items included as category members were found primarily for the less typical items, with inclusion rates varying as a function of both age and typicality level. The absolute level of typicality judgments increased with age, although correlations between the children’s and college students’ ratings were generally significant for all three children’s groups, with average correlations increasing somewhat with age. It was suggested that the rating data would be useful to developmental investigators interested in children’s processing of category information.     

Population psychology in perspective(1)

Many aspects of population, from fertility regulation to migration, may be viewed as examples of human behavior occurring within a particular socio-economic and environmental context, and thus appropriate for psychological research. Especially considered in this paper are (1) the current status of population growth and the importance of population processes as research topics for psychologists; (2) basic assumptions concerning the complementarity of behavioral and biomedical sciences in population research; (3) behavioral science contributions, specifically from psychology; and (4) recommendations for cooperative multidisciplinary efforts.     

Responding maintained by the opportunity to attack during an interval food reinforcement schedule

Pigeons responded in a two-key situation. Responses on the right key (food key) were reinforced with food presentation on a response-initiated fixed-interval schedule, (i.e., first response after a fixed period of time was reinforced); responses on the left key (target key) were reinforced on a fixed-ratio schedule (i.e., every nth response was reinforced) with the presentation of a target bird that could be attacked. When the interval value of the food reinforcement schedule was varied from 1 min to 5 min, both the rate of attack responding on the target bird and the rate of responding on the target key were a function of the interval value. Responding on the target key was not maintained by the stimulus change associated with target availability, and was successively extinguished and reconditioned by removing and returning the target bird to the restraining box. When food was delivered independently of behavior, responding on the target key either remained unchanged or decreased, but was not eliminated. Responding on the target key was not maintained in the absence of an intermittent schedule of food presentation.     

Assertive training: An adjunct to fluency shaping

“Assertive Training” has been utilized as an adjunct therapy in a six week residential program at Walter Reed Army Medical Center. The speech pathology staff in conjunction with the psychology staff determined that a persistent problem with long term success after patients were dismissed from therapy was largely due to a “behavioral deficit” in their interpersonal verbal confrontations. The anxiety resulting from such communication failure simply chips away at the self confidence needed to maintain a working level of fluency, resulting in a “snowballing” effect back to dysfluency.

Thus, the goals and procedures of assertive training for stutterers are discussed as a means to shape more effective skills in relating to others in difficult situations. Pre, post and six month follow-up data are presented.     

The effects of varied acoustic parameters on performance in dichotic speech perception tasks

Five dichotic speech experiments were conducted with normal adult listeners in which the signal to one or both ears was degraded by manipulation of intensity, signal-to-noise ratio, or bandwidth parameters. Results suggest that: (1) performance of the ear (or ears) receiving the degraded signal can be predicted from the monaural identifiability of the stimuli, and (2) dichotic performance, at least in stop consonant-vowel tests, reflects an additive central process which combines speech information from the two ears.     

Some situational determinants of the motives attributed to the person who performs a helping act

Two studies were directed at the assessment of donor motives for and appropriateness and evaluation of an unsolicited helping act directed at a high versus a low power person by self or other Results of the first study demonstrated no differences between self and other, but highly significant differences between high and low power on all three dependent measures, with an act directed at a high power person being seen as more self-seeking and being more negatively evaluated. A manipulation of liking for other in the second study resulted in significant differences between self and a disliked other on all three measures, with more negative attributions and evaluations of die disliked other As predicted, there were no differences between self and a liked other Power differences remained significant over all conditions of self and other Results were considered not to be attributable to trans-situational need states of the low power person, however, the act was consistently viewed as more appropriate when directed at a low power person.     

The use of limit theorems in paired comparison model building

The Thurstone and the Bradley-Terry models, both initially advanced on intuitive grounds, have proved useful in the analysis of paired comparisons. The psychological meaning of these models and their relation to one another is unclear, but they fit data. Stevens has observed that there may be two basic mechanisms of discrimination 1) additive and 2) substitutive. We advance two corresponding mathematical models: that experienced sensation is 1) the sum of a large number of independent signals and 2) the maximum of a large number of independent signals. These assumptions yield 1) Thurstone's model and 2) the model of Bradley-Terry. Psychological interpretations of the various parameters, in terms of sensation, present themselves in a natural manner. Thus this paper presents a theory which unifies and interprets two paired comparison models that have proved useful in fitting experimental data.This research was supported in part by a National Science Foundation Grant GP 3807 and by the Army, Navy, and Air Force under ONR Contract # NONR-988(08), Task Order NR 042-004 with the Florida State University.