Season of birth and childhood intelligence: findings from the Aberdeen Children of the 1950s cohort study.

Background: In this study, 2 main hypotheses have been put forward to explain the variation in childhood intelligence or school performance by season of birth. In the first hypothesis, it is suggested that it is due to school policy concerning school entry, whereas the second suggests that a seasonally patterned exposure such as temperature, maternal nutrition, or infection during critical periods of brain development have a lasting effect on intelligence.

Aims: To determine whether childhood performance on tests of different domains of intelligence is patterned by season of birth and to examine possible mechanisms for any associations.

Family socioeconomic position at birth and future cardiovascular disease risk: findings from the Aberdeen Children of the 1950s cohort study.

Objectives: We assessed the association of father's social class, recorded at the time of birth, with coronary heart disease and stroke in a British cohort of 11106 individuals born in the 1950s.

Methods: Survival analysis was used to relate social class at birth to the occurrence of either fatal or nonfatal coronary heart disease or stroke.

Results: Rates of coronary heart disease and stroke increased across the social class distribution from highest to lowest, and patterns of association were similar for the 2 outcomes.

The cognitive cost of being a twin: evidence from comparisons within families in the Aberdeen children of the 1950s cohort study.

Objectives: To determine whether twins have lower IQ scores in childhood than singletons in the same family and, if so, whether differences in fetal growth explain this deficit.

Design: Cohort study.

Setting: Scotland.

Birth weight is inversely associated with incident coronary heart disease and stroke among individuals born in the 1950s: findings from the Aberdeen Children of the 1950s prospective cohort study.

Background: Birth weight is inversely associated with cardiovascular disease risk factors, but few studies have examined the association with disease end points, in particular with stroke risk. Furthermore, previous studies demonstrating an inverse association between birth weight and coronary heart disease (CHD) risk have been conducted on populations born in the early part of the 20th century, when infant mortality rates were high. If the environmental factors associated with improvements in infant mortality rates over the last century explain the inverse association between birth weight and CHD risk, one would expect weaker associations in more contemporary birth cohorts.

Early life predictors of childhood intelligence: evidence from the Aberdeen children of the 1950s study.

Objective: To identify the early life predictors of childhood intelligence.

Design: Cohort study of 10 424 children who were born in Aberdeen (Scotland) between 1950 and 1956.

Results: Social class of father around the time of birth, gravidity, maternal age, maternal physical condition, whether the child was born outside of marriage, prematurity, intrauterine growth, and childhood height were all independently associated with childhood intelligence at ages 7, 9, and 11.