An adjacency effect in free recall

An adjacency effect was demonstrated at a high level of significance in the free recall, by 123 subjects, of a list of 40 high-frequency nouns presented in varying order on successive trials. The phenomenon referred to as the adjacency effect consists of the fact that when a subject is given repeated trials of study and free recall of a list of words (always presented in a different order), the probability of recalling a given item is greater when the item is presented temporally adjacent to an item which is already learned (as evidenced by recall on the previous trial) than when the item stands temporally between other items which are not yet learned. The enhancement of recall is greater when the item is presented between two previously learned items. The implications of the adjacency effect for verbal learning theory, particularly for the serial-position effect in serial learning and the concepts of interference and neural consolidation, are discussed.     

Race differences and type II errors: A comment on Borkowski and Krause

Magnitude comparisons of black-white differences on a variety of cognitive tests give a somewhat different picture of the results of a small-sample study by Borkowski and Krause (1983), who based their conclusions mainly on significance tests. Some of the critical variables in the study consisted of differences scores with unacceptably low reliability, inclining the results toward the favored hypothesis, namely, that the locus of the difference between blacks and whites in psychometric intelligence lies in metaprocesses, or the executive system, and not in the elementary cognitive processes. The results actually show fairly comparable black-white differences in measures of both types of processes.     

Humphreys's attenuated test of Spearman's hypothesis

Humphreys's test of Spearman's hypothesis (viz., that the size of the standardized black-white differences on various psychometric tests is positively related to the tests' loadings on g, the general intelligence factor) is methodologically weak. It is based on comparison of a fairly representative sample of the black population of U.S. school children with a highly selected sample of the white school population, representing the lowest 15 to 20% of whites in socio-economic status (SES). A fair test of the hypothesis requires that the black and white samples should not be selected on any g-correlated variable, such as SES. Selection attenuates and distorts the relationship between tests' g loadings and the magnitude of the standardized mean black-white differences on the tests. Other unorthodox conditions in Humphreys's study, such as performing factor analysis on the test-score means of various arbitrary demographic groups instead of on individual test scores inflates tests' g loadings and biases the test of Spearman's hypothesis by restriction of reliable variance in g loadings. Humphreys's study cannot be considered a proper replication of Jensen's examination of Spearman's hypothesis in 11 different studies comprising 74 different tests, which consistently bears out Spearman's hypothesis.     

Predicting young women's role preference for parenting and work

Young women's motivations for two sex-role options were predicted with scores describing perceived rewards/costs of parenting. Using a sequence of multiple regression analyses it was found that the reward-cost perceptions of parenting and work were predictors of the two motivational options. Individual rewards/costs of parenting and work items were better predictors than summed items. It was found that a preference for the career choice was produced by not viewing parenting as rewarding. The preference for parenting choice was influenced most by perceiving parenting as rewarding. The perceived cost and rewards of work were not predictors of a career choice. The items found to be the best predictors for either the parenting or career choice all dealt with perceptions of parenting. It was concluded that these parenting perceptions are the key elements for young women's role motivations.     

The development of compensatory stepping skills in children

The development of the ability to use the step for balance recovery was studied among twenty-five 9- to 19-month-old children. The children were grouped according to walking experience (4 levels) and exposed to backward support surface translations, 8 cm in amplitude, under 3 velocity conditions: 15, 20, and 25 cm/s. New walkers (up to 2 weeks' walking experience) used the step infrequently and ineffectively in response to threats to balance. Intermediate walkers (1-3 months' walking experience) showed an increasing use of the step and significant improvement in step execution compared with new walkers. Advanced walkers (>3; months' walking experience) experienced no falls throughout the protocol, capturing balance with feet-in-place or step responses under all perturbation conditions. A significant developmental transition in the emergence of the compensatory step occurred between the new walker and the intermediate walker experience levels, that is, within the first 3 months of walking experience. Three to 6 months' experience was required for the development of an effective stepping response. A concomitant change in mediolateral stability paralleled the emergence of compensatory stepping.