Baseline: 1991 (February) – 1994 (March)
First follow-up: 1993 (May) – 1996 (May)
Second follow-up: 1995 (April) – 1998 (May)
Third follow-up: 1997 (April) – 2000 (May)
Fourth follow-up: 1999 (December) – 2002 (March)
702 (552 with biological samples)
Wave 1: 351 twin pairs
Wave 2: 235 pairs (568 individuals)
Wave 3: 144 pairs (430 individuals)
Wave 4: 315
Wave 5: 43 pairs (222 individuals)
79-98
79-98
Questionnaires, physical measures, biosamples (blood)
Longitudinal
Questionnaires, physical measures, biosamples (blood)
Health and functional ability, cognitive functioning, personality, personal control and mental health, interpersonal relationships, and functional ratings.
Etiology of individual differences among twin-pairs age 80 and older:
Health and functional capacity
Cognitive functioning
Psychological well-being
Personality
Personal control
To examine whether the relative impact of genetic influences decreases, increases, or remains at the same magnitude for various aspects of bio-behavioral functioning in the old-old.
Social Science, Psychology, Medicine
University of Gothenburg, Department of Psychology
Porf. Linda Hassing
Professor, PI of OCTO-Twin
Department of Psychology
University of Gothenburg
Tel: +46 31 786 4258
linda.hassing@psy.gu.se
https://www.gu.se/forskning/octo-twin-studien-en-studie-av-tvillingpar-80-ar-och-aldre-i-sverige
McClearn, G. E., Johansson, B., Berg, S., Pedersen, N. L., Ahern, F., Petrill, S. A., et al. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science, 276, 1560-1563.
Johansson B, Whitfield K, Pedersen NL, Hofer SM, Ahern F, McClearn GE. 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. J Gerontol B Psychol Sci Soc Sci. 1999 May;54(3):P173-9. doi: 10.1093/geronb/54b.3.p173. PMID: 10363039