Findings on happiness in Plomin et al. (1993): study US Colorado 1986

Publication
Author(s)Plomin, R.; Braungart, J.M.; Campos, J.J.; Corley, R.P.; DeFries, J.; Emde, R.N.; Fulker, D. W.; Kagan, J.; Reznick, J.S.; Robinson, J.L.; Zahn-Waxler, C.
TitleGenetic change and continuity from fourteen to twenty months: The MacArthur Longitudinal Twin Study
SourceSociety for Research in Child Development; Child Development, 1993, 64, 1354-1376
Investigation
PublicSame-sex twins, Colorado, United States, followed from 14 to 20 months, 1986-1989
Last assesment1989
Survey nameNot available
 "The MacArthur Longitudinal Twin Study"
SampleNon-probability purposive sample
 90% of sample is Caucasian, 1% is black, other participating families are primarily Hispanic
Respondents N =398
 199 same-sex twin pairs, 106 female pairs (61 monozygotic, 45 dizygotic), 94 male pairs
Non ResponseNot available
AssesmentBehavioural observation
 At 14 months: observation at home, 2 weeks later observation in laboratory
Happiness measure(s) used
Full textTime sampled ratings of positive and negative affect made from video recordings of child behavior; 30 second intervals across 15 minutes of free play and 1minute intervals for 4 alternate 5 minute segments of the Bayley test Assessment of discrete behaviors; observation schedule not reported Rated on 4 step scale, scale labels not reported
ClassificationA-AB-mi-tsb-?-4-a
Author's labelHedonic tone, positive and negative
Page in publication1337, 1362
RemarksAffect Balance computed by WDH team; 14 months: boys: M=0.89; girls: M=1.01 20 months: boys: M=1.05; girls: M=1.09 (overall mean computed by WDH team) Positive Affect: 14 months: boys: M=2.27 sd=.24; girls: M=2.35 sd=.25 20 months: boys: M=2.35 sd=.25; girls: M=2.38 sd=.27 Negative Affect: 14 months: boys: M=1.38 sd=.33; girls: M=1.36 sd=.31 20 months: boys: M=1.30 sd=.27; girls: M=1.29 sd=.31
Finding used in
nation ranks
Yes
 On original range 1 - 4On range 0 - 10
Mean1.01
Standard deviation


Full textTime 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
ClassificationA-CA-mi-tsb-v-7-a
Author's labelOverall Mood
Page in publication1357, 1362
Remarks14 months: boys: M=4.6 sd=1.1; girls: M=4.9 sd=1.1 20 months: boys: M=4.9 sd=1.1; girls: M=5.0 sd=1.2
Finding used in
nation ranks
Yes
 On original range 1 - 7On range 0 - 10
Mean4.856.42
Standard deviation1.131.88


Correlational findings

Author's labelSubject Code
Finding
Subject description
GenderG01aaSex (male vs female)
Happiness at 14 and 20 monthsH04ab01aRecent happiness (< 1 year ago)
Happiness of twin siblingsH08ac04Happiness of sibblings
Happiness of twin siblingsF01af02dHappiness of siblings, also classified as above ↑