An empirical taxonomy of visual illusions

A classification system for visual-geometric illusions, based upon the interrelationships between behavioral responses to various distortions was created. Forty-five illusion configurations were presented to 221 observers. Factor analysis revealed that there are five classes of illusions. A secondorder analysis revealed that visual distortions are ultimately reducible to two global types of distortions: illlusions of extent and illusions of shape or direction.     

Prism adaptation with simultaneous receipt of normal input

A 20-diopter vertically-displacing prism was worn on one eye in conjunction with plane glass on the other. Five groups ofSs differed in the density of a neutral filter worn over one eye. No aftereffect could be measured in either eye in any condition where the luminance of the “normal” field was equal to or greater than that of the prism field. As the luminance of the “normal” field is decreased below that of the prism field, the magnitude of aftereffect increases and is measurable in each eye.     

Should assessment center dimension ratings be mechanically-derived?

This study examined the relationship between consensusderived and mechanically-derived assessment center ratings using a sample of 110 police candidates. It was determined that the two sets of dimension ratings were highly correlated (medianr=.83). Further, the mechanically-derived and the consensus-derived assessment ratings both correlated with the overall assessment ratings (OAR) at .71. It was estimated that the organization in this study could save $6137.92 a year, and $36.89 per assessee by eliminating the team meeting (consensus decision-making).     

The Importance of Contraceptive Attributes Among College Students

This study assessed how ratings of the importance of contraceptive attributes varied with gender, age, relationship status, and contraceptive method usually used. In a classroom setting, 210 male and 217 female university students completed the 55-item Contraceptive Attribute Questionnaire (CAQ). Significant differences on importance ratings were found between women and men, age groups, women using barrier methods and women using the pill, and by relationship status. The underlying dimensions of the CAQ were investigated through factor analysis, and somewhat different factors emerged for men and women. Implications for the provision of family planning services to college students are discussed.     

Caffeine,impulsivity, and memory scanning: A comparison of two explanations for the Yerkes-Dodson Effect

Two explanations for the Yerkes-Dodson Effect (1908) were tested. Easterbrook (1959) proposed that arousal reduces the range of cue utilization. Thus, arousal should interfere with the capacity for simultaneous (dual) memory scans. In contrast, Humphreys and Revelle (1984) proposed that arousal facilitates sustained information transfer but interferes with short-term memory. Arousal should thus reduce the time needed to prepare to respond but increase the time needed to scan memory. Either caffeine or placebo was given to 78 subjects who differed in impulsivity. They completed three versions of a memory-scanning task: two single-task versions (physical and category matches) and one dual-task version (either type of match). As predicted by Humphreys and Revelle, relative to placebo, caffeine lowered the intercept (p<.01), suggesting facilitation of sustained information transfer, but increased the slope (p<.05), suggesting impairment of access to short-term memory, of the regression of reaction time on log-transformed memory-set size. That caffeine had a main effect on slopes and on intercepts but did not interact with type of task suggests that arousal does not necessarily disrupt dual-task performance.     

An application of Strong's validity criteria to basic interest scales

E. K. Strong, Jr.'s (Vocational interests of men and women, Stanford, Calif.: Stanford Univ. Press, 1943) four propositions for interest-inventory validity andJ. L. Holland's (Making vocational choices: A theory of careers, Englewood Cliffs, N.J.: Prentice-Hall, 1973) hexagonal classification system were synthesized in order to adapt a traditional procedure for determining the construct validity of occupational interest scales to the validation of basic interest scales. The procedure was tested using a sample of 4035 males and 3671 females whose interest inventory results as high school students and whose majors as college seniors could be assigned Holland codes. Results of the study indicate that this procedure can be used to assess the construct validity of inventories using basic interest scales.     

Book reviews

Early Behavior: Comparative and Developmental Approaches. Edited by H. W. Stevenson, E. H. Hess, and H. L. Rheingold. London and New York: Wiley. 1967. Pp. xii + 303 75s.

Current Research in Motivation. Edited by Ralph Norman Haber. London and New York: HOlt, Rinehart and Winston. Pp. xii + 800. £5

Language and Thought. Edited by Donald C. Hildum. London: Van Nostrand, Insight Book No. 37. 1967. Pp. vi + 2 00. $1.95. 16s.

Hormones and Behavior. Edited by Richard E. Whelan. London: Van Nostrand. Insight Book No. 39. I967. Pp. vi + 266. $2.95. 24s.     

Personality and Physical Health: An Introduction

This article provides a rationale for research on personality as a contributing factor in the development of physical disease. A brief history of major developments from the 1930s to the present is then provided. Special attention is given to shifts in conception regarding whether particular dispositions are related to specific physical disorders or whether these dispositions increase general illness susceptibility. The paper ends with a brief orientation to the other papers and commentaries in this special issue.     

Main and interaction effects of metallic toxins on classroom behavior

This study investigated the relationships of metal levels and metal combinations to children's classroom behavior. Hair-metal concentrations of lead, arsenic, mercury, cadmium, and aluminum were determined in 80 randomly selected elementary-age children, who were also rated by their classroom teacher on the Walker Problem Behavior Identification Checklist (WPBIC). Parents were interviewed to control for confounding variables that may have affected behavioral development. Regression analysis indicated that the set of metals was significantly related to increased scores on four of the five WPBIC subscales and on the total scale, with lead being a major contributor to four of the six dependent measures. Metal combinations were significantly related to increased scores on the WPBIC subscales measuring acting-out, disturbed peer relations, and immaturity, and on the total scale. A continuing reexamination of metal poisoning concentrations is needed because metal levels and metal combinations previously thought harmless may be associated with nonadaptive classroom behavior.