Biomedical subjects

Lawrence D Cohn

Publications and source records attributed to Lawrence D Cohn.

3 recordsLinked to original sources

PubMed2004

Intelligence and maturity: meta-analytic evidence for the incremental and discriminant validity of Loevinger's measure of ego development.

This review examined whether Loevinger's measure of personality (ego) development is equivalent to the measurement of intelligence. The authors conducted a meta-analysis of 52 correlations between ego level scores and intelligence test scores (retrieved from 42 studies involving 5,648 participants). The weighted average correlation between ego level and intelligence ranged from.20 to.34, depending on the intellectual ability assessed (e.g., verbal intelligence). Adjusting for measurement unreliability increased these values only minimally. The authors also reviewed 16 studies that examined the association between ego level and various criterion variables (e.g., aggressive behavior) after statistically controlling for the effects of intelligence. Ninety-four percent of the tests revealed significant relations between ego level and criterion variables after controlling for intelligence, indicating that ego development and intelligence are not interchangeable constructs. These findings do not support recent speculations concerning the limited value of stage models of maturity, social development, and moral reasoning.

Adolescent↗

PubMed2003

How meta-analysis increases statistical power.

One of the most frequently cited reasons for conducting a meta-analysis is the increase in statistical power that it affords a reviewer. This article demonstrates that fixed-effects meta-analysis increases statistical power by reducing the standard error of the weighted average effect size (T.) and, in so doing, shrinks the confidence interval around T.. Small confidence intervals make it more likely for reviewers to detect nonzero population effects, thereby increasing statistical power. Smaller confidence intervals also represent increased precision of the estimated population effect size. Computational examples are provided for 3 effect-size indices: d (standardized mean difference), Pearson's r, and odds ratios. Random-effects meta-analyses also may show increased statistical power and a smaller standard error of the weighted average effect size. However, the authors demonstrate that increasing the number of studies in a random-effects meta-analysis does not always increase statistical power.

Humans↗

PubMed2002

A program to increase seat belt use along the Texas-Mexico border.

A school-based, bilingual intervention was developed to increase seat belt use among families living along the Texas-Mexico border. The intervention sought to increase seat belt use by changing perceived norms within the community (i.e., making the nonuse of seat belts less socially acceptable). The intervention was implemented in more than 110 classrooms and involved more than 2100 children. Blind coding, validity checks, and reliability estimates contributed to a rigorous program evaluation. Seat belt use increased by 10% among children riding in the front seat of motor vehicles in the intervention community, as compared with a small but nonsignificant decline in use among control community children. Seat belt use among drivers did not increase.

Child↗