Significant category clustering in free recall

Frender and Doubilet suggest that Bousfield's ratio of repetitions (RR) is the best measure of clustering in free recall presently available. Conditioning only on the number of words recalled, they determine the mean ofRR in the absence of clustering. In this note the null variance ofRR is presented. This permits development of conservative significance tests based on the Cramér inequality.     

The Effects of Censorship on Attitude Change: The Influence of Censor and Communication Characteristics1

The effects of censor characteristics and audiences' initial agreement with a censored communication on attitude change and desire to hear a communication were investigated. Subjects were informed that a communication taking a position with which they had originally agreed or disagreed had been censored. The censor was either an attractive or unattractive agent and his expertise on the topic of the speech was either high or low. The results indicated that in all cases except one, censorship led to an increased desire to hear the communication and attitude change toward the position of the communication. In the one exceptional case, when an attractive expert censor forbade a communication with which the audience disagreed, the subjects decreased their desire to hear the speech and did not change their attitudes on the topic of the communication. The results were interpreted as indicating that censorship arouses both reactance and balancing attempts but that balancing will be observed only in limited situations.     

Varying temporal placement during CS of an added stimulus correlated with non-delivery of UCS

This experiment extends Pavlov’s method of contrasts for training a stimulus discrimination to the case of the cardiac conditional response in the rhesus monkey. It explores the parameter of temporal placement of an additional stimulus (“CS₂”) within a 10-sec CS (or “CS₁”), with the appearance of the former stimulus on any trial signalling the absence of UCS (electric shock) on that trial. This experimental paradigm is a parallel to that of the “intruded stimulus” studies in operant conditioning. In both cases, several ways of describing the function of the added stimulus are possible, but all seem reducible to the same operational terms. Data were taken in the present study with respect to the form and latency of the cardiac rate changes produced by intrusion of CS₂ (light), across a range of placements varying from simultaneity with CS₁ (a different light) onset to two sec before UCS would have been delivered. The control of CS₂ over the cardiac rate CR was occasionally exhibited with a latency as short as three beats after stimulus onset. The order of CS₂ temporal placements to which a subject was exposed was a factor in determining the form of the conditioned cardiac rate response to CS₁.     

The effects of censorship and attractiveness of the censor on attitude change

The effects of censoring a communication, overriding the censor, and the attractiveness of the censor on the potential audience's attitude and desire to hear the communication were studied. Subjects were told that a speech which they were to have heard had been censored by a positively, negatively, or neutrally evaluated group. Some subjects were told that the experimenter had decided to override the censor and that they would hear the communication. Other subjects were told they would not hear the censored communication. The results indicated that censorship, regardless of the attractiveness of the censor, caused the potential audience to change their attitudes toward the position to be advocated by the communication and to increase their desire to hear that communication. These effects were interpreted as resulting from the arousal of psychological reactance. When the censor was overriden and the audience felt that they would hear the communication, their desire to hear it decreased. Further, subjects who had been told that a positively evaluated group had censored the speech changed their attitudes away from the position to be advocated by the communication while subjects who believed that a negative group had censored the speech changed their attitudes toward the position of the communication. These results were interpreted as evidence of cognitive balancing.     

Social perception and signal detectability theory: Group influence on discrimination and usage of scale

Summary The influence of social motivation on perception was operationalized as group pressure on the usage of a 4-point scale by which subjects discriminated two stimulus situations in a procedure analogous to signal detection experiments. After a pretest, only those subjects were taken who preferred the left end of the scale. During each main session three confederates influenced one selected subject by the opposite scale preference after each of his judgments had been given. The preformance level of the confederates was equalized to that of the naive subject in the pretest. Both the possibility of an ex post check and the resulting conflict generated motives leading to an increased performance in the experimental group but to a decrease in the control group (without influence). No subject resisted to influence. The theoretical relevance for social perception is discussed.

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Zusammenfassung Der Einfluß sozialer Motivation auf die Wahrnehmung wurde als Gruppendruck auf den Gebrauch einer 4-Punkte-Skala operationalisiert, auf der Versuchspersonen (Vpn) zwei Reizsituationen wie in Signal-Detection-Experimenten unterschieden. Nach einem Vorversuch wurden nur solche Personen genommen, die das linke Ende der Skala bevorzugten. In allen Hauptversuchen beeinflußten 3 Mitwisser des Versuchsleiters eine ausgewählte Vp durch eine gegensätzliche Bevorzugung der Skala nach jeder Antwort der Vp. Das Leistungsniveau der Mitwisser entsprach dem Niveau der naiven Vp im Vorversuch. Die Möglichkeit der nachträglichen Überprüfung und der resultierende Konflikt erzeugten Motive, die zu einer erhöhten Leistung in der experimentellen Gruppe, in der Kontrollgruppe (ohne Einfluß) jedoch zu einer Abnahme führten. Keine Vp widerstand dem Einfluß. Die theoretische Bedeutung für die soziale Wahrnehmung wird diskutiert.