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Sibling Ideological Influence: A Natural Experiment

Published online by Cambridge University Press:  25 March 2011


Siblings are a potentially important source of political socialization. Influence is common, especially among younger siblings and those close in age, who tend to interact most frequently. This suggests that the positions of an individual's next-older sibling will hold particular sway. In policy questions with a gender gap, then, those whose immediately older sibling is a sister will be more likely to absorb the typically female preference; those born after a brother, the male preference. Evidence from the United States shows that this pattern holds for general left–right orientation as well as for the preferred balance between public and private sectors. Just as American women are more likely to lean left and to see government intervention positively, so are Americans whose next-older sibling is female.

Research Article
Copyright © Cambridge University Press 2011

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52 This concept is undefined for eldest siblings and only children. Regressions including older-sibling sex as an independent variable accordingly drop 1,081 respondents (from the survey's 2,992) from the dataset. An alternative coding that does not drop these people might consider the ‘feminizing effect of older sibling’, thus being valued at +1 for those with a next-older sister, −1 for those with a next-older brother, and 0 for those with no older siblings. This alternative produces substantially similar results to those reported.

53 Henderson and Berenbaum, ‘Sex-Typed Play in Opposite-Sex Twins’.

54 Twinship is assumed when the sibling born in the same year is a full sibling, and the respondent's month of birth is between March and October.

55 In seventeen cases, the sex of the next-older full sibling differs from that of the next-older non-full sibling; a further 154 respondents have no older full siblings but do have older non-full siblings.

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60 In the original GSS, higher values on the first question denote relatively more faith in the state rather than in private enterprise. The coding is reversed here to maintain consistency of meaning across the dependent variables: positive values always associate with less support for state intervention.

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65 Reported results are also robust to the inclusion of age squared, which is itself insignificant, except for the dependent variable about the government generally doing more to solve social problems.

66 Combining the non-farm countryside category with the farm category does not appreciably alter the reported results.

67 All respondents living abroad at age 16 are grouped into a single category with its own indicator.

68 Other potentially interesting factors, such as direct measures of parental views and how they might have shaped both the respondent's and sibling's outlook, are not available in this dataset.

69 Ordered logistic regressions produce substantively similar results for all OLS regressions in this study; OLS models are retained for ease of interpretation.

70 As both the sex variable and the sibling-sex variable are simple indicators, these estimated effects are simply the size of the coefficients (in points on the seven-point scale).

71 Education is less consistent in its effects, probably because of collinearity with income.

72 Despite its lack of statistical significance, the effect of sibling sex here is still substantively non-trivial. The coefficients imply that the difference between an older brother and an older sister roughly equals the effect of a fifteen-year change in age.

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76 Siblings’ months of birth are not available.

77 Unprocessed, the median respondent's age difference with the next-older sibling is two years, just over half the mean age difference of 3.45 years; the maximum difference is thirty-one years.

78 Similar results hold for using the models without income and education.

79 All four models of Table 2 produce comparable results if run with the interaction term: a continued negative coefficient for having a next-older sister, and smaller positive coefficients for the interaction.

80 This range includes 96.5 per cent of the observed values in the dataset.

81 Standard errors on the first differences were calculated using CLARIFY; see King, Gary, Tomz, Michael and Wittenberg, Jason, ‘Making the Most of Statistical Analyses: Improving Interpretation and Presentation’, American Journal of Political Science, 44 (2000), 341355CrossRefGoogle Scholar.

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