The Conflict Between Aristotelian and Galileian Modes of Thought in Contemporary Psychology

Kraepelin combined the constant method and the method of limits to avoid the inconvenience of the former and the response bias of the latter. The use of this approach together with Guttman scaling provides a method that requires few observations, is easy to administer and score, and can be applied to a variety of measurement situations. Examples are given of its use for point of subjective equality, aesthetic preference, and thresholds.     

Preference for signalled reinforcement

Key pecking was reinforced on a two-component multiple schedule. A variable-interval schedule controlled reinforcement in both components. During one component, access to reinforcement was preceded by a tone; in the other component, a standard unsignalled schedule was in effect. After performance stabilized, subjects were given a choice between the signalled and unsignalled schedules. They were placed in the chamber with the unsignalled schedule in effect on the right key. A single response on the left, or changeover, key produced the signalled schedule for 1 min. Both pigeons in Experiment I pecked the changeover key at a rate sufficient to remain under the signalled schedule for over 90% of the session. Removing and reintroducing the tone demonstrated that the changeover-key responses were due to the occurrence of the tone. In Experiment II, when pecking the changeover key produced the unsignalled schedule, pecking the changeover key declined. The results may be explained either in terms of Hendry's information hypothesis or as escape from an intermittent positive reinforcement schedule.     

Thickness and the Koffka ring effect

Over seven decades ago Gestalt psychologist Kurt Koffka described a remarkable effect: when a contiguous gray ring is placed on a background half of one shade of gray, half of another, the ring appears homogeneous. However, if the ring is slightly divided, the two halves of the ring appear different shades of gray, the half of the ring on the darker background appearing lighter than the half of the ring on the lighter background. The Gestalt principle of continuity is used to explain this effect. We show that when the ring is made thinner it appears heterogeneous even when contiguous. We also illustrate this in the additional material with a colored background with more than two regions.     

Evaluating the predictive validity of a single stimulus engagement preference assessment.

Most preference assessments require individuals to choose among two or more stimuli. More recently, the duration of engagement with items has been used as an index of preference. In the current study, the predictive validity of a single stimulus engagement (SSE) preference assessment was evaluated with 4 individuals. Stimuli were presented singly for a brief period while engagement with that stimulus was recorded. Although SSE preference rankings closely matched paired stimulus preference assessment rankings for only 2 of the 4 participants, relative preference rankings based on duration of engagement predicted relative reinforcer effectiveness for all participants in a subsequent concurrent‐schedule reinforcer assessment. The SSE procedure took less time to administer than the paired stimulus procedure but produced less stable preference rankings across administrations. The SSE procedure may be appropriate for individuals who have difficulty selecting one stimulus from among two or more stimuli, and it may be well suited for evaluating activities that are difficult to present in a paired stimulus format.     

Internal versus external references with respect to perception of stimuli on the body surface

Previous studies on the determinants of locus of perception of stimuli on the body have suggested that the position of the stimulus has a significant effect whether a subject perceives a tactile pattern as seen from inside or outside the body. However, it is possible that previous investigators confounded stimulus location--dorsal or frontal--and experimenter's position--behind or in front of the subject. Using 42 male subjects in a 2 X 2 design, the effects of experimenter's position and stimulus location were studied by a new technique for inferring locus of perception. Experimenter's position, rather than stimulus location, affects subjects' locus of perception. Perception of stimuli on the body involves three independent factors, the demand characteristics of the experiment, the manner in which an individual perceives the boundaries of his own body, and an individual's ability to adopt the experimenter's perceptual standpoint.     

Attitudes among adolescents in a Swedish city toward some sexual crimes

Using data from a representative sample of adolescents in grade ten in Uppsala, the fourth largest city in Sweden, attitudes toward a number of (criminal) sexual acts are studied. These data are contrasted with those from a sample of patients at a school gynecological clinic. It is found that for both samples, only a very limited number of the eight discussed acts are considered to be criminal by the adolescents. Although at least seven or eight acts are criminal in Swedish law, only two acts are considered criminal by about half of the respondents. These acts are pedophilia and rape after petting. The same questions were used by Kutchinsky in 1969 when on behalf of the U.S. Congress Commission on Obscenity and Pornography he studied inhabitants in Copenhagen, Denmark. When comparing data from Uppsala Sweden 1978 with data from Copenhagen, Denmark 1969 we find that Swedish adolescents in the late seventies, on the whole are much less likely to call the discussed acts criminal. The only exception is rape after petting, which in Copenhagen in the late sixties was the act least often seen as criminal but in the Uppsala study in the late seventies it was one of the two acts most often claimed to be criminal. Finally, the effects of coital experience and the effect of sexual knowledge on the percieved criminality of the acts are considered.