Childhood intelligence, educational attainment and adult body mass index: findings from a prospective cohort and within sibling-pairs analysis

Abstract

Background:The mechanisms underlying the observed association of childhood intelligence with body mass index (BMI) are unclear and few studies of this association have been prospective in design. Methods: Prospective study in a birth cohort of 5467 individuals who were born in Aberdeen, Scotland between 1950 and 1956 and who responded to a follow-up survey in 2001. Comparison of associations within sibling pairs of the same family to associations between different families in 643 sibling pairs (1286 individuals) who are participants in the main cohort. Results: Childhood intelligence (age 7 years) and educational attainment were both inversely associated with adult BMI (mean age 48 years): the sex-and age-adjusted mean change in adult BMI per s.d. of intelligence was À0.35 kg/m 2 (95% CI: À0.49, À0.21 kg/m 2 ) and per unit increase in educational category (seven categories) was À0.28 kg/m 2 (95% CI: À0.34, À0.22). On adjustment for education the association between childhood intelligence and adult BMI attenuated to the null (À0.03 kg/m 2 (À0.19, 0.13 kg/m 2 )); other potential confounding or mediating factors had little or only modest effects on this association. The association between education and adult BMI was not affected by adjustment for childhood intelligence or other potential covariates. The within sibling-pair effect of education on adult BMI (À0.06 kg/m 2 (95% CI: À0.26, 0.14)) was weaker than the effect between different families (À0.37 kg/m 2 (95%CI: À0.58, À0.17)), P-value for difference of within sibling and between family effect ¼ 0.03. Conclusions: The association of childhood intelligence with adult BMI is attenuated to the null on adjustment for educational attainment, whereas the association of educational attainment with adult BMI appears to be independent of childhood intelligence and other measured covariates. However, our family analyses suggest that fixed family and neighbourhood factors, which are closely matched in siblings of a similar age, explain much of the association between greater educational attainment and lower adult BMI.

Childhood Cognition and Risk Factors for Cardiovascular Disease in Midadulthood: The 1958 British Birth Cohort Study

“…In Britain, as in many other countries, social and behavioral pathways are intertwined because of the strong influence of social circumstances on behaviors. Not surprisingly, effects of adjustment for adult social circumstances were found to be substantial, as reported for associations of childhood cognition with all-cause mortality, 9 obesity, 5,6 and risk factors investigated here.…”

“…3,4 Associations between higher childhood cognition and lower levels of adiposity have been observed, with some studies investigating mediation of factors such as adult education. [5][6][7][8] Explanations have been proposed for associations between childhood cognition and adult mortality or morbidity: first, there may be common causes of cognition and adult disease, including childhood socioeconomic position; second, childhood cognition predicts later educational and occupational attainment, which in turn influences exposure to hazardous environments that affect risk of adult disease; and third, childhood cognition affects the extent to which individuals acquire or act on knowledge about protective or health-damaging behaviors linked to disease. 9 Few studies have examined explanations in detail, largely because of limited data availability on relevant factors.…”

Intelligence moderates neural responses to monetary reward and punishment

“…Furthermore, measures of intelligence (IQ) correlate with important life outcomes pertaining to educational achievement, job performance, wealth, and health status (Deary et al 2007;Gottfredson 1997;Gottfredson and Deary 2004;Lawlor et al 2006). Importantly for modern theories of decision making, differences in IQ consistently predict parameters describing individuals' preferences with respect to risk and temporally delayed rewards (Burks et al 2009;Rustichini et al 2009;Shamosh et al 2008;Shamosh and Gray 2008), suggesting that these fundamental decision parameters may be critically influenced by common neurobiological mechanisms related to intelligence.…”

Educational differences in cardiovascular mortality: The role of shared family factors and cardiovascular risk factors

“…A recent study (Ariansen I, In press) carried out in a population overlapping the present found that one third of educational differences in CVD risk factors could be explained by early life factors shared by siblings. Lawlor et al [26] reported an attenuation of the association between BMI and education in within siblingship analyses. Kamphuis et al [27] found that childhood circumstances more or less completely influenced cardiovascular mortality through known CVD risk factors.…”