Research has demonstrated that individual differences in numeracy may have important consequences for decision making. In the present paper, we develop a shorter, psychometrically improved measure of numeracy-the ability to understand, manipulate, and use numerical information, including probabilities. Across two large independent samples that varied widely in age and educational level, participants completed 18 items from existing numeracy measures. In Study 1, we conducted a Rasch analysis on the item pool and created an eight-item numeracy scale that assesses a broader range of difficulty than previous scales. In Study 2, we replicated this eight-item scale in a separate Rasch analysis using data from an independent sample. We also found that the new Rasch-based numeracy scale, compared with previous measures, could predict decision-making preferences obtained in past studies, supporting its predictive validity. In Study, 3, we further established the predictive validity of the Rasch-based numeracy scale. Specifically, we examined the associations between numeracy and risk judgments, compared with previous scales. Overall, we found that the Rasch-based scale was a better linear predictor of risk judgments than prior measures. Moreover, this study is the first to present the psychometric properties of several popular numeracy measures across a diverse sample of ages and educational level. We discuss the usefulness and the advantages of the new scale, which we feel can be used in a wide range of subject populations, allowing for a more clear understanding of how numeracy is associated with decision processes.

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Maternal diabetes during pregnancy may affect behavioral and intellectual development in the offspring. The associations between gestational ketonemia in the mother and a lower IQ in the child warrant continued efforts to avoid ketoacidosis and accelerated starvation in all pregnant women.

With the increasing use of cocaine in the United States, there has been growing concern regarding its effects on the fetuses and neonates of pregnant cocaine abusers. Twenty-three cocaine-using women enrolled in a comprehensive perinatal-addiction program were divided into two groups: those using cocaine only and those using cocaine plus narcotics. These two groups were compared with a group of women who had used narcotics in the past and were maintained on methadone during pregnancy, and with a group of drug-free women. All four groups were similar in maternal age, socioeconomic status, number of pregnancies, and cigarette, marijuana, and alcohol use. Their medical histories indicated that the cocaine-using women had a significantly higher rate of spontaneous abortion than the women in the other two groups. In the pregnancies under study, four cocaine-using women had onset of labor with abruptio placentae immediately after intravenous self-injection of cocaine. Neonatal gestational age, birth weight, length, and head circumference were not affected by cocaine use. However, the Brazelton Neonatal Behavioral Assessment Scale revealed that infants exposed to cocaine had significant depression of interactive behavior and a poor organizational response to environmental stimuli (state organization). These preliminary observations suggest that cocaine influences the outcome of pregnancy as well as the neurologic behavior of the newborn, but a full assessment will require a larger number of pregnancies and longer follow-up.