Study Robinson et al. (2001): study US 1986
- Public
- Toddlers, same-sex twins, Colorado, United States, followed from 14 to 24 months of age, 1986-1989
- Survey name
- Unnamed study
- Sample
- Respondents
- N = 400
- Non Response
- Assessment
-
Behavioural observation
behavioral observation at home and in laboratory, recorded on video tape; parental reports in questionnaire
Correlate
- Authors's Label
- Happiness of twin sibling
- Our Classification
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-
- Remarks
- MZ = monozygotic (non-identical twins) DZ = dizygotic (identical twins)
- Related specification variables
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-
- Operationalization
- Happiness of twin sibling assessed in the same way using time sampling of expressive behavior
Observed Relation with Happiness
at 14 months: r=+.50
at 20 months: r=+.55
at 24 months: r=+.26
at 14 months: r=+.39 p<0.01
at 20 months: r=+.34 p<0.01
at 24 months: r=+.18 p<0.05
at 14 months: h²=+.22 ns
at 20 months: h²=+.40 p<.05
at 24 months: h²=+.16 ns
h² computed using regression method of DeFries & Fulker (1985)
at 14 months: c²=+.28 ns
at 20 months: c²=+.14 ns
at 24 months: c²=+.10 ns
see Plomin et al. (1990, 1993);
c² computed by using regression method of DeFries & Fulker (1985)