New Findings from the Wisconsin Longitudinal Study

In their recent article in SSM – Population Health, CDHA external affiliate Pamela Herd (Georgetown) and Kamil Sicinski (UW–Madison) note that with an aging population and increasing prevalence of dementia, unpacking the relationship between educational attainment and later life cognitive functioning is increasingly important. Yet, the authors note, this relationship is not well understood.

Using Sibling Models to Unpack the Relationship Between Education and Cognitive Functioning in Later Life,” uses data from the Wisconsin Longitudinal Study (WLS), a long-term study that captures data on a random sample of 1 in 3 high school graduates from the class of 1957 in Wisconsin and a selected sibling. The WLS provides an opportunity to study the life course, intergenerational transfers and relationships, family functioning, physical and mental health and well-being, and morbidity and mortality beginning in late adolescence.

Through an examination of sibling data from the WLS, Herd, who led the study from 2010–21, and Sicinski, an associate scientist at WLS, aimed to uncover why older adults with greater educational attainment have relatively preserved cognitive functioning. Using the WLS, the researchers tested whether family environments, adolescent IQ, and genetic factors, as well as adult health behaviors and health impacted later life cognition.

They found little evidence that early life genetic endowments and environments, or midlife health and health behaviors, explain the relationship. However, Herd and Sicinski found that adolescent cognition influences late life cognition, in part, via education and that education’s influence is independent of adolescent cognition.

Support for Herd and Sicinski’s new research came from the NIA-funded grant Wisconsin Longitudinal Study-Initial Lifetime’s Impact on Alzheimer’s Disease and Related Dementias (WLS-ILIAD Study). For WLS-ILIAD, researchers and clinicians began tracking the progression into dementia (AD dementia, non-AD dementia) of participants in WLS. The project aims to clarify the influence of the early life period on dementia risk—as well as adult behaviors that can offset risk. The findings will provide supporting evidence for policy and individual level interventions that could modify the risk for AD/ADRD. Herd and CDHA affiliate Sanjay Asthana (UW School of Medicine) are PIs for the grant working closely with co-investigators Robert Hauser (Professor Emeritus of Sociology), Amy Kind (UW School of Medicine), and Carol Roan (WLS).