Subject code: H08ac04

Study | Loehlin & Nichols (1976): study US 1963 |

Title | Heredity, Environment and Personality. A Study of 850 Sets of Twins. |

Source | University of Texas Press, 1976, Austin, USA |

Public | Adolescent same-sex twins, USA, 1963 |

Sample | Probability stratified sample |

Non-Response | 29 % |

Respondents N = | 850 |

Correlate | |

Author's label | Happiness of twin sibling |

Page in Source | 14 |

Our classification | Happiness of sibblings, code H08ac04 |

Operationalization | A Happiness of Identical twins a brothers b sisters B Happiness of Fraternal twins a brothers b sisters |

Observed distribution | N for happiness = A: 486 Aa: 204, Ab: 282, B: 320 Ba: 130, Bb: 190 N for % cheerful & satisfied = A: 509, Aa: 216, Ab: 293, B: 330, Ba: 135, Bb: 195 |

Remarks | All twins are same sex |

Observed Relation with Happiness | ||

Happiness Measure | Statistics | Elaboration/Remarks |

O-HP-g-sq-v-7-a | r=+.37 | Happiness of identical twins (average r) - brothers r = +.41 - sisters r = +.34 |

O-HP-g-sq-v-7-a | r=+.21 | Happiness of fraternal twins (average r) - brothers r = +.12 - sisters r = +.27 Difference betwee correlations among identical & fraternal twins significant (p<05) |

O-HP-g-sq-v-2-b | r=+.26 | Happiness of identical twins (average r) - brothers r = +.14 - sisters r = +.35 |

O-HP-g-sq-v-2-b | r=+.09 | Happiness of Fraternal twins(average r) - brothers r = +.17 - sisters r = +.03) Difference between correlations among identical & fraternal twins significant (p<.05) |

O-HP-g-sq-v-2-c | r=+.16 | Happiness of identical twins - brothers r = +.07 - sisters r = +.23 |

O-HP-g-sq-v-2-c | r=+.07 | Happiness of fraternal twins - brothers r= +.11 - sisters r= +.05 Difference between correlations among identical & fraternal twins ns Significance tests computed by us, assuming that these samples are a probability sample of a wider population of twins. |

Appendix 1: Happiness measures used

Code | Full Text |

O-HP-g-sq-v-2-b | Selfreport on single question: Which of the following adjectives do you consider to be descriptive of yourself? Circle the number besides any adjective that you might use in describing yourself to someone else. Your behavior will vary with situation of course, so circle the numbers besides adjectives that apply to you frequently, even though they may not apply all the time. Work rapidly putting down your first thoughts. Cheerful 1 no (not circled) 2 yes (circled) Item in longer personality inventory |

O-HP-g-sq-v-2-c | Selfreport on single question: Which of the following adjectives do you consider to be descriptive of yourself? Circle the number besides any adjective that you might use in describing yourself to someone else. Your behavior will vary with situation of course, so circle the numbers besides adjectives that apply to you frequently, even though they may not apply all the time. Work rapidly putting down your first thoughts. Satisfied 1 no (not circled) 2 yes (circled) Item in longer personality inventory |

O-HP-g-sq-v-7-a | Selfreport on single question: Below are a number of dimensions on which people can vary. Please rate yourself on each dimension as honestly as you can. Many of the traits depend on the situation of course, but try to rate yourself as you usually are. Happy-unhappy 7 very happy 6 fairly happy 5 slightly happy 4 neither or both 3 slightly unhappy 2 fairly unhappy 1 very unhappy Item in longer personality inventory Numbers reversed original presentation (happy 1, unhappy 7) |

Appendix 2: Statistics used

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. |

Ruut Veenhoven, World Database of Happiness, Collection of Correlational Findings, Erasmus University Rotterdam.

https://worlddatabaseofhappiness.eur.nl