Sentencing severity with mock jurors: Predictive validity of three variable categories

Previous studies have identified three categories of variables which influence decisions of mock jurors: type of crime, defendant characteristics, and personal characteristics of jurors. This study manipulated the following variables towards the ends of assessing their influence on mock jurors' sentencing severity: premeditated vs. unpremeditated murder, black vs. white defendant, low SES vs. high SES defendant. Only defendant SES predicted sentencing severity: low SES defendants were assigned significantly longer sentences than high SES defendants. None of the measures of juror characteristics correlated with sentencing severity. Failure to replicate significant relationships with most of these variables and sentencing severity suggest that results of studies which manipulate only one variable dimension may overestimate the influence of these variable dimensions in mock jurors' decisions.     

Sex differences in impulsivity and intellectual ability

Literature on sex differences in impulsivity has tended to focus on differences between groups, while ignoring relationships beyond zero order correlations. The purpose of this study was to evaluate Maccoby's hypothesis (1966) of opposite-direction correlations where the relationship between a set of variables (e.g., impulsivity and intellectual ability) is curvilinear, with males and females being systematically distributed on opposite sides of the curve. The Primary Mental Abilities (PMA) and Matching Familiar Figures tests were administered to 44 males and 49 females. The relationship between all of the PMA subtests and impulsivity was curvilinear for males, but linear for females on all but one of the subtests. The importance and implications of examining distribution differences rather than group differences are discussed.Support for this study has come from the Office of Research Administration, University of Kansas, Grant Number 3581-5038. This paper was presented in part at the meeting of the American Psychological Association, Chicago, August 1975, Division 7.     

Tables of d′ for variable-standard discrimination paradigms

Signal detection theory (SDT) allows a bias-free measure of sensitivity, d′, to be simply estimated from discrimination data when certain conditions are met. The computation is not straightforward, however, in several popular discrimination designs, such as two- and four-interval same-different designs and the ABX design. The present tables, derived from the SDT models of Macmillan, Kaplan, and Creelman (1977), make possible the estimation of d’ from these complex discrimination designs.     

Effect of effort and latent extinction on resistance to extinction

Sixty-four male Wistar rats were given acquisition training in an enclosed straight-alley runway which could be adjusted for angles of inclination. The 2×2×2 design involved two angles of inclination in acquisition (0° and 40°) and two angles of inclination in extinction (0° and 40°). Between acquisition and extinction, half the subjects were exposed to a latent extinction procedure and half served as controls. Number of responses in a 30-min extinction session was an inverse function of effort required in extinction. Additionally, latent extinction procedures resulted in reduced resistance to extinction, but only when the effort conditions of acquisition and extinction were constant. When the effort conditions of acquisition and extinction were dissimilar, latent extinction procedures resulted in increased resistance to extinction. The results raise questions about the nature of the learning which occurs during latent extinction training.     

Intracranial cannulation of small animals

Special difficulties are encountered when attempting to provide intracranial cannulation of small animals that have floating or fragile skull bones. The technique described was developed for mice but seems applicable to other species. The cannula system is inexpensive and easy to use. A wound clip anchor seems superior to either skull screws or bonded acrylic, producing less damage to the brain and no necrosis of bone or tissue on the wound margin. Patency data up to 25 days is presented, and the system is as efficacious as other techniques.     

Psychological adjustment in transvestism and transsexualism

Thirty-four transvestites who had shown fetishistic arousal in association with cross-dressing were categorized into two groups on the intensity of feminine gender identity. The two transvestite groups were compared to a group of 24 non-fetishistic transsexuals who sought a full sex change operation. Ss in all three groups reported greater current psychological stress and scored higher on neuroticism and introversion than Ss in a normal population. A large proportion of Ss in the three groups had previously sought psychiatric help. The degree of psychological maladjustment was not related to the intensity of feminine gender identity.     

The role of marking when reward is delayed

Two-choice spatial discrimination by rats is enhanced if a salient stimulus marker occurs immediately after every choice response and again after a delay interval (Lieberman, McIntosh & Thomas, 1979). Three experiments further explore this effect. Experiment 1 found that the second marker is unnecessary. Experiment 2 found that a marker presented before a response is as effective as one presented after. Both effects could be explained in terms of markers focusing attention on subsequent cues. Experiment 3, however, found that markers after choice enhance learning even when no discriminative cues are present following the marker. Markers thus appear to initiate both a backward search through memory and attention to subsequent events; both processes help to identify events that might be related to the unexpected marking stimulus.