| Study | Emde et al. (1992): study US Colorado 1986 |
| Title | Temperament, Emotion, and Cognition at Fourteen Months: The MacArthur Longitudinal Twin Study |
| Source | Child Development, Vol. 63, No. 6 (Dec., 1992), pp.1437-1455 |
| URL | http://www.jstor.org/stable/1131567 |
| Public | 14 months aged, same-sex twin pairs, Colorado, United States, 1986-1989 |
| Sample | Non-probability purposive sample |
| Non-Response | |
| Respondents N = | 398 |
| Correlate | |
| Author's label | Happiness of Twin siblings |
| Page in Source | 1445, 1447, 1448 |
| Our classification | Happiness of siblings, code F01af02d |
| Operationalization | at 14 months, twin pairs were first observed at home and 2 weeks after that in the laboratory at the Institute for Behavioral Genetics in Boulder, behavior was videotaped and rated afterwards; parents completed questionnaire in the time between the home & lab session; |
| Observed distribution | N: 99 monozygotic twin pairs, 99 dizygotic twin pairs |
| Remarks | monozygotic (MZ) = identical dizygotic (DZ) = non-identical Heritability (h²): the extent to which observed variance in behavior can be attributed to genetic influence: -> doubling the difference between the MZ and DZ correlations, because MZ twins are identical genetically, whereas the genetic correlation for DZ twins is assumed to be +.50 Shared Environment (c²): shared environmental influences (c²), estimated in the twin method as twin resemblance not explained by heritability: twice the DZ correlation minus the MZ correlation (only detects major effects of shared environment) for details of computations see DeFries & Fulker, 1985 |
| Observed Relation with Happiness | ||
| Happiness Measure | Statistics | Elaboration/Remarks |
| A-CA-mi-tsb-v-7-a | r=+.19 p < .01 | Monozygotic Twins |
| A-CA-mi-tsb-v-7-a | r=+.02 ns | Dizygotic Twins |
| A-CA-mi-tsb-v-7-a | Heritability component: h²=+.34 (ns) Shared environment component: c²=-.15 (ns) | |
| Code | Full Text |
| A-CA-mi-tsb-v-7-a | Time sampling of prevalent mood during free play and Bayley test. Average of observations at 30 second intervals across 15 minutes of free play and 1 minute intervals for 4 alternate 5 minute segments of the Bayley test Rated on 7 step scale, scale labels not reported |
| Symbol | Explanation |
| r | PRODUCT-MOMENT CORRELATION COEFFICIENT (Also "Pearson's correlation coefficient' or simply 'correlation coefficient') Type: test statistic. Measurement level: Correlate: metric, Happiness: metric Range: [-1; +1] Meaning: r = 0 « no correlation , r = 1 « perfect correlation, where high correlate values correspond with high happiness values, and r = -1 « perfect correlation, where high correlate values correspond with low happiness values. |