Skip to main content
Log in

Midlife Study of the Louisville Twins: Connecting Cognitive Development to Biological and Cognitive Aging

  • Original Research
  • Published:
Behavior Genetics Aims and scope Submit manuscript

Abstract

The Louisville Twin Study (LTS) began in 1958 and became a premier longitudinal twin study of cognitive development. The LTS continuously collected data from twins through 2000 after which the study closed indefinitely due to lack of funding. Now that the majority of the sample is age 40 or older (61.36%, N = 1770), the LTS childhood data can be linked to midlife cognitive functioning, among other physical, biological, social, and psychiatric outcomes. We report results from two pilot studies in anticipation of beginning the midlife phase of the LTS. The first pilot study was a participant tracking study, in which we showed that approximately 90% of the Louisville families randomly sampled (N = 203) for the study could be found. The second pilot study consisted of 40 in-person interviews in which twins completed cognitive, memory, biometric, and functional ability measures. The main purpose of the second study was to correlate midlife measures of cognitive functioning to a measure of biological age, which is an alternative index to chronological age that quantifies age as a function of the breakdown of structural and functional physiological systems, and then to relate both of these measures to twins’ cognitive developmental trajectories. Midlife IQ was uncorrelated with biological age (− .01) while better scores on episodic memory more strongly correlated with lower biological age (− .19 to − .31). As expected, midlife IQ positively correlated with IQ measures collected throughout childhood and adolescence. Additionally, positive linear rates of change in FSIQ scores in childhood significantly correlated with biological age (− .68), physical functioning (.71), and functional ability (− .55), suggesting that cognitive development predicts lower biological age, better physical functioning, and better functional ability. In sum, the Louisville twins can be relocated to investigate whether and how early and midlife cognitive and physical health factors contribute to cognitive aging.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1

Similar content being viewed by others

References

Download references

Funding

Funding was supported by National Institute on Aging (US) Grant no. R03AG048850-01 and National Institute on Aging Grant no. R01 AG063949-01.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Christopher R. Beam.

Ethics declarations

Conflict of interest

Christopher R. Beam, Eric Turkheimer, Deborah Finkel, Morgan E. Levine, Ebrahim Zandi, Thomas M. Guterbock, Evan J. Giangrande, Lesa Ryan, Natalie Pasquenza, and Deborah Winders Davis declare that they have no competing interests.

Human and Animal Rights and Informed Consent

No experimental animals were used in the study. This study was approved by the Institutional Review Board of the University of Southern California and the University of Louisville.

Additional information

Edited by Yoon-Mi Hur.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Beam, C.R., Turkheimer, E., Finkel, D. et al. Midlife Study of the Louisville Twins: Connecting Cognitive Development to Biological and Cognitive Aging. Behav Genet 50, 73–83 (2020). https://doi.org/10.1007/s10519-019-09983-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10519-019-09983-6

Keywords

Navigation