This study focused on individual differences among the oldest-old. Most studies of aging concentrate on individuals between 50 and 75 years of age. Growing numbers survive beyond 80, and can be considered successful agers.

Project description

Normative studies of aging report large individual differences among 80 year olds, however these projects focus on describing the average 80-90 year old. Whereas SATSA has provided unique information concerning genetic and environmental effects for aging among the young-old, OCTO-Twin is concerned with the etiology of individual differences among the old-old.
The study is designed much the same as SATSA, with questionnaire, health assessments, and extensive cognitive testing. All 80 year old and older twin pairs in Sweden, where both in the pair are still alive, have been recruited to participate in the study, which was completed with 5 waves of data collection at 2 year intervals. Of primary interest is the importance of genetic and environmental factors contributing to continued well-being, health, and functional capacity in this unique material.

Financing: NIH (NIA)

Project leader


Inst. for Gerontology, Jönköping, Sweden; Pennsylvania State University


Substantial genetic influence on cognitive abilities in twins 80 or more years old.
McClearn GE, Johansson B, Berg S, Pedersen NL, Ahern F, Petrill SA, et al
Science 1997 Jun;276(5318):1560-3

Origins of individual differences in episodic memory in the oldest-old: a population-based study of identical and same-sex fraternal twins aged 80 and older.
Johansson B, Whitfield K, Pedersen NL, Hofer SM, Ahern F, McClearn GE
J Gerontol B Psychol Sci Soc Sci 1999 May;54(3):P173-9

The importance of genetic and environmental effects for self-reported health symptoms: a 30-year follow-up considering survival and selection effects.
Pedersen NL, Steffensson B, Berg S, Johansson B, McClearn GE
J Aging Health 1999 Nov;11(4):475-93

Quantitative genetic analysis of biobehavioral markers of aging in Swedish studies of adult twins.
Finkel D, Pedersen NL, Berg S, Johansson B
J Aging Health 2000 Feb;12(1):47-68

Petrill, S. A., Plomin, R., Berg, S., Johansson, B., Pedersen, N. L., Ahern, F., et al. (1998). The genetic and environmental relationship between general and specific cognitive abilities in twins age 80 and older. Psychological Science, 9(3), 25-31.