The repetition effect in time judgments is not a function of the intensity of the stimulus defining the interval: implications for an arousal theory

College students (N = 17 per group) estimated the durations of time intervals ranging from 8 to 20 sec. Intervals were defined by tones of 35, 55, and 75 db for each of three groups. The estimates of all groups declined across trials, but the degree of decline did not differ as a function of stimulus intensity. These data call into question the view that the repetition effect is attributable to a decrement in general arousal.     

Transfer of effort across behaviors

A series of experiments investigated the effects of required force and number of responses per reinforcer upon the subsequent performance of a second behavior. In the first experiment, a group of rats required to complete five round trips in an alley per food pellet subsequently bar-pressed for food at a greater rate than a group rewarded for each round trip or a control group that did not receive the alley experience. In the second experiment, a group required to apply a 70-g bar-press force subsequently shuttled for food at a greater rate than a group required merely to touch the lever or a control group that did not undergo the lever-press manipulation. The third experiment found that the force effect persisted across all five test sessions and was attributable to differences both in response speed and interresponse time. The fourth experiment found that both the necessary bar-press force and number of bar presses per reward affected subsequent shuttling in extinction. Two alternative interpretations of these results were compared: (a) the degree of accustomed effort per reinforcer becomes a generalized component of instrumental behavior or (b) high effort increases the habituation frustration-produced disruptive responses.     

Some correlates of stuttering severity judgments

Thirteen adult male stutterers recorded the Amplifier Passage on high-quality audiotape. One sentence from each recording was paired with one sentence from each of the remaining 12 recordings. The resulting 78 sentence pairs were presented to eight speech-language pathologists who were asked to judge which stutterer in each pair was more severe and to rate the confidence of each of these judgements. The confidence ratings were analyzed by means of the individual differences model of multidimensional scaling. The results suggested that reading rate and the number of intrasentence pauses were important parameters in determining the severity of stuttering.     

Effects on weight reduction of strong monetary contracts for calorie restriction or weight loss

Thirty-one severely obese adults participated in behavioral weight control groups. In three groups utilizing powerful monetary contracts, subjects deposited substantial sums of money which were returned contingent on either attendance, calorie restriction, or weight loss. Subjects in a fourth no-contract control condition made no monetary deposits. Weight and calorie contract groups lost an average of nearly 20 lb in 10 weeks. They did not differ from each other, but both produced significantly more weight loss than the attendance contract group. High dropout rates in the no-contract condition precluded statistical evaluation of this group. Results are discussed in terms of the potential clinical value of contracting procedures.     

Intelligence research at the interface between differential and cognitive psychology: Prospects and proposals

There seems to be widespread agreement among theoreticians and methodologists alike that new approaches to studying intelligence should somehow combine the differential and cognitive (information-processing) approaches that have been used in the past, and that the combination should somehow enable the investigator to isolate components of intelligence that are elementary (at some level of analysis). Researchers disagree, however, as to how the differential and cognitive approaches should be combined, and consequently, in how elementary components of intelligence should be isolated and in what they are. How does an investigator choose from among the multiple paths available for theory and research? In this article, I propose some guidelines that may help investigators make informed choices. The article is divided into three major parts. In the first, I propose guidelines for choosing from among various methodologies for studying intelligence, and then describe briefly at least some of the methods that meet (or come close to meeting) these guidelines. In the second part, I propose guidelines for the specification of subtheories (and eventually, full-fledged theories) of intelligence, and illustrate how these guidelines can be met. Finally, I describe the direction in which I believe our subtheories and methods should lead us.     

An investigation of racial differences on vocational variables among college women

This study used a sample of black and white college women matched on Duncan's (1961) socioeconomic indicator ratings to explore possible racial differences on vocationally relevant variables. There were no differences between the groups on age or educational level. The distribution of the parents' occupations by Holland type and the distribution of the subjects by their VPI type appeared to be quite similar. There were no significant differences based on: the relationship of the parents' occupational types to the subjects' VPIs: the relationship between the subjects' VPI types and their occupational choice or college major; the estimated likelihood of reaching the career goal; satisfaction with career choice or college major; and scores on two recent scales designed to measure vocational indecision. While no differences were found on the number of possible factors listed that might impede career goals, the distribution of the most important of these factors indicated there were differences between the two groups. These findings are discussed relative to their implications for interpreting previous research and carrying out future studies.     

Developmental changes in mental rotation

Subjects from Grades 3, 4, 6, and college judged whether pairs of stimuli were identical or mirror-image reversals. One stimulus of a pair was presented upright; the other was rotated 0 to 150° from the standard. The pairs were either alphanumeric symbols or unfamiliar, letter-like characters of the type found on the PMA Spatial Ability Test. Response latencies were measured. The primary results were that (a) the speed of mental rotation increased with development, (b) unfamiliar characters were rotated more slowly than alphanumeric characters, by approximately the same amount at each grade, and (c) unfamiliar characters were encoded and compared more slowly than alphanumeric symbols, by an amount that declined with development. The results are discussed in terms of the component processes that underlie developmental change and individual variation in mental rotation skill.