In a well-designed experiment, random assignment of participants to treatments makes causal inference straightforward. However, if participants are not randomized (as in observational study, quasi-experiment, or nonequivalent control-group designs), group comparisons may be biased by confounders that influence both the outcome and the alleged…

Economic disadvantage is associated with multiple risks to early socioemotional development. This article reviews research regarding family stress frameworks to model the pathways from economic disadvantage to negative child outcomes via family processes. Future research in this area should expand definitions of family and household to incorporate…

Article focused on R. L. Gregory's theory of distortion illustions and his defense of that theory. (RK)

The author examines the relationship of averaged cortical evoked responses and intelligence. The results show there is a small statistically significant relationship but more research is needed before individual prediction can take place. (DE)

This article is an expanded version of a book review which originally appeared in "Self & Society." In it the author criticizes the methodology and findings of Lieberman, Yalom, and Miles on their book about encounter groups. (Editor/RK)

Author reviewed a challenge by Hollan to his "set/net" distinction. (Author/RK)

Eysenck has stated that dysthymics were introverted and psychopaths were extraverted. This study tested this hypothesis. (Author)

The purpose of this article was to show how Krantz's test (for threshold theories of signal detection) can be applied to examine the discrete-state assumption of the models proposed by Bernbach and Kintsch for recognition memory and to review some critical experimental data. (Author/RK)

The present study was designed to give an unambiguous assessment of a possible asymmetry in bilateral transfer of the skill of printing inverted and reversed letters. (Author)

Supported in part by a grant (M-628) from the United States Public Health Service, National Institutes of Health.

THIS DOCUMENT QUESTIONS THE PSYCHOLOGICAL VALIDITY OF DISJUNCTIVE CONCEPTS. A DISJUNCTIVE CONCEPT IS DEFINED AS AN AGGREGATE CHARACTERIZED BY THE PRESENCE OF EITHER ONE OF SEVERAL ATTRIBUTES OR ALL OF THEM, WHERE THE DIFFERENT ATTRIBUTES DO NOT SHARE ANY ELEMENTS IN COMMON. THE AUTHOR FEELS THAT NATURAL HUMAN CATEGORIES ARE TYPICALLY NOT…

Three experiments investigated the ability of seven-month-olds to categorize the facial expressions of happiness, fear, and surprise, which were depicted by degrees of intensity. Happiness could be distinguished in mild and extreme forms, but fear was difficult to discriminate from happiness or surprise. (SKC)

Discusses Walberg's psychological theory of educational productivity, which is based on the Cobb-Douglas economic production function. The empirical finding that the educational production function is approximately homogeneous of degree one in the productivity factors, in accordance with theory, is noted, and it is shown how this agreement could…

Psychology textbooks frequently present Wolfgang Kohler's two-stick experiment with chimpanzees as having demonstrated insight in learning. Studies that replicated Kohler's work support his findings but not his interpretation in terms of insightful solution. The uncritical inclusion of Kohler's insight interpretation in texts is not warranted in…

Discusses research showing that material people learn when in a high arousal state and material they learn when in a normal arousal state is subsequently best recalled when they are in a similar arousal state. Speculates that this effect may partially underlie mood cuing, mood-related material from memory. (EKN)