Location in cognitive and residential space at age 70 reflects a lifelong trait over parental and environmental circumstances: The Lothian Birth Cohort 1936

Though mental ability tends to be relatively stable throughout the lifespan, many still argue that late life cognitive function largely reflects education, social class, and environmental circumstances. Instead, it may be that early life cognitive function contributes to each of these in turn, as well as to late life cognitive function. This paper reports the contribution of IQ measured at age 11, adjusting for childhood measures of parental social status, to variation in educational and social class attainment in adulthood, and to cognitive function and environmental quality at age 70. Participants were the1091 members of the Lothian Birth Cohort 1936. They were born in 1936 and participated in the Scottish Mental Survey 1947. They were living independently in the general area of the City of Edinburgh, Scotland at the time of recruitment and assessment for this study at about age 70. Ages 11 and 70 IQs assessed using the same Moray House Test were correlated .69, and then .61 after adjustment for participants’ own educational and social class attainment, as well as for those of their fathers in childhood. Age 11 IQ was correlated .30 with age 70 environmental quality, and it remained correlated at .15 after adjustment. The attainment measures had significant but much smaller effects on both outcome measures. We conclude that both cognitive function and life circumstances at age 70 reflect lifelong cognitive function to a greater degree than they do life circumstances.