Gene by Environment Interplay in Cognitive Aging

Abstract

In this chapter, we reconsider existing theoretical models of Gene–Environment (GE) interplay and view them through the lens of a lifespan perspective, focusing on the shifting nature of the environments that impact cognitive function throughout adulthood. Existing evidence for GE interplay in cognitive aging is evaluated from this vantage point, including investigations that tap recent advances in genotyping and gene expression. The extent to which genetic factors are actually correlated with environments that provide more or less support for cognitive skills is unknown. However, educational and occupational attainment as well as leisure activities and exercise may reflect GE correlational processes that deserve further examination from a life course perspective. Emerging evidence is perhaps a bit more encouraging with respect to G × E processes: e.g., higher education and participation in leisure and physical activities may lower the risk of cognitive decline in those who already carry the APOE e4 risk allele. Familiality of methylation levels and telomere lengths, suggests that genetically driven differential sensitivities to environments (e.g., stress) may be important to individual differences in cognitive aging, but detailed investigations of specific environmental factors is minimal as yet. Large-scale efforts to study G × E influences on aging outcomes are underway, and predicted to contribute in important ways to the emerging literature on GE interplay using behavioral genetics and molecular methods.