| 1. |
|
|
| 2. |
|
|
| 3. |
- Beam, Christopher R., et al.
(författare)
-
Midlife study of the Louisville Twins : Connecting cognitive development to biological and cognitive aging
- 2020
-
Ingår i: Behavior Genetics. - : Springer. - 0001-8244 .- 1573-3297. ; 50:2, s. 73-83
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Finkel, Deborah, et al.
(författare)
-
Socioeconomic status impacts genetic influences on the longitudinal dynamic relationship between temperament and general cognitive ability in childhood : The Louisville Twin Study
- 2022
-
Ingår i: Child Development. - : John Wiley & Sons. - 0009-3920 .- 1467-8624. ; 93:2, s. e135-e148
-
Tidskriftsartikel (refereegranskat)abstract
- The current analysis investigates genetic and environmental influences on the bidirectional relationships between temperament and general cognitive ability (GCA). Measures of GCA and three temperament factors (persistence, approach, and reactivity) were collected from 486 children ages 4-9 years (80% white, 50% female) from the Louisville Twin Study from 1976 to 1998. The results indicated a bidirectional dynamic model of temperament influencing subsequent GCA and GCA influencing subsequent temperament. The dynamic relationship between temperament and GCA arose primarily from shared genetic variance, particularly in families with higher socioeconomic status, where input from temperament contributed on average 20% to genetic variance in GCA versus 0% in lower SES families.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Womack, Sean R., et al.
(författare)
-
Co-recovery of physical size and cognitive ability from infancy to adolescence : A twin study
- 2024
-
Ingår i: Child Development. - : John Wiley & Sons. - 0009-3920 .- 1467-8624. ; 95:4, s. 1367-1383
-
Tidskriftsartikel (refereegranskat)abstract
- This study tested phenotypic and biometric associations between physical and cognitive catch-up growth in a community sample of twins (n = 1285, 51.8% female, 89.3% White). Height and weight were measured at up to 17 time points between birth and 15 years, and cognitive ability was assessed at up to 16 time points between 3 months and 15 years. Weight and length at birth were positively associated with cognitive abilities in infancy and adolescence (r's =.16–.51). More rapid weight catch-up growth was associated with slower, steadier cognitive catch-up growth. Shared and nonshared environmental factors accounted for positive associations between physical size at birth and cognitive outcomes. Findings highlight the role of prenatal environmental experiences in physical and cognitive co-development.
|
|
| 12. |
- Giangrande, E. J., et al.
(författare)
-
Genetically informed, multilevel analysis of the Flynn Effect across four decades and three WISC versions
- 2022
-
Ingår i: Child Development. - : John Wiley & Sons. - 0009-3920 .- 1467-8624. ; 93:1, s. e47-e58
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigated the systematic rise in cognitive ability scores over generations, known as the Flynn Effect, across middle childhood and early adolescence (7–15 years; 291 monozygotic pairs, 298 dizygotic pairs; 89% White). Leveraging the unique structure of the Louisville Twin Study (longitudinal data collected continuously from 1957 to 1999 using the Wechsler Intelligence Scale for Children [WISC], WISC–R, and WISC–III ed.), multilevel analyses revealed between-subjects Flynn Effects—as both decrease in mean scores upon test re-standardization and increase in mean scores across cohorts—as well as within-child Flynn Effects on cognitive growth across age. Overall gains equaled approximately three IQ points per decade. Novel genetically informed analyses suggested that individual sensitivity to the Flynn Effect was moderated by an interplay of genetic and environmental factors.
|
|
