Psychological development and aging
The purpose of this group is to describe development and change in psychological characteristics over the life-course and to identify early- and later-life biological, psychological and social determinants of development and change in psychological characteristics.
Because early development shapes the adult individual and because aging takes place throughout the lifespan, we consider life course studies essential to understand individual differences in aging. Consequently, we conduct studies of early development and determinants of early development, studies of continuity and change in psychological characteristics such as personality traits and cognitive ability during adult life and studies of determinants of change and aging over the lifespan.
Essentially, we believe that individual differences among older and elderly people can only be fully understood by including a life course perspective. Interventions to increase an active and healthy lifestyle in old people may be useful, but we have to remember that the most important factors influencing aging may have influenced the individual long before he or she enters old age.
- Early developmental milestones – in particular milestones related to language – are associated with both young adult and midlife intelligence. Early determinants of cognitive development – such as birth weight – also predict midlife cognitive ability.
- Early life biomedical and social factors – in particular early childhood socioeconomic position – predict midlife allostatic load, presumably reflecting "wear and tear" across the lifespan. The association appear to be stronger in women than men for both biomedical factors (birth complications) and social factors (not living with parents when one year old).
- Individual differences in cognitive ability or intelligence are surprisingly stable over most of the adult lifespan, including high age. This suggests that individual differences in cognitive aging may be relatively small – compared to the substantial variance in cognitive ability that can be observed in young adults. This may partly explain why it has proven difficult to identify consistent predictors of individual differences in cognitive decline – in spite of consistent age-related change in mean levels of cognitive performance.
- Quality of life has profound effects on public health through various links between quality of life of adults and the development of disease and longevity. Several factors early in life, such as infant socio-economic status and birth weight may affect the quality of life in midlife.
Studies based on the Copenhagen Perinatal Cohort
The cohort comprises 9125 individuals born in 1959-61, and it has proved essential in analysis of early development and in analyses aimed at identifying early factors that influence personality and cognitive development. In evaluating associations with midlife characteristics it has been essential to link the Perinatal Cohort with the CAMB database.
Studies based on the LIKO-15 data collection
This database includes information on 2500 men with both draft board intelligence scores (assessed about age 20) and late midlife intelligence scores (assessed about age 61). The database enables analyses of age-related changes in cognition with a primary focus on lifestyle factors, including alcohol consumption.
Studies based on the DiaKO-19 data collection
This database includes information on 2400 men with both draft board intelligence scores (assessed about age 20) and late midlife intelligence scores (assessed about age 66). The database enables analyses of age-related changes in cognition with a primary focus on type 2 diabetes and depression. LiKO-15 and DiaKO-19 are two separate databases with no overlap in participants.
Studies based on the DCD database
This database includes draft board information on more 700.000 Danish men. We use it to analyse associations between young adult intelligence and educational and occupational career with a special focus on unsuccessful educational and occupational achievement. It is also used for analysing predictors of alcohol use disorder and other psychiatric disorders.