[4] In 1983 he obtained a PhD at the University of Edinburgh with the thesis "Social work and the elderly: a problem of definition"[5] written for the Stuart Macgregor Memorial Prize.

[8] In 2012, the journal Annual Review of Psychology published an overview of the field of intelligence research, authored by Deary.

Interview and biomedical data were also collected from the cohort members to allow wide-ranging investigation of the causes and consequences of differences in cognition across the lifespan.

Using data from the Lothian Birth Cohort studies, Deary and colleagues have investigated the effects of ageing on cognition.

In addition, genetic and brain imaging data from members of the Cohorts allow investigation of the biological causes of differences in intelligence and cognitive ageing.