ArticlePDF Available

Does sibling gender affect personality traits?

Authors:

Abstract and Figures

This paper studies whether sibling gender affects personality traits. We use the idea that if parents decide to have a second child, it is random whether they will have a boy or a girl. Therefore, the relationship between the second-born sibling's gender and the first sibling's personality traits is causal. We employ longitudinal data from a large British cohort which is followed from birth onwards. The dataset includes personality traits at age 10 and 16. Our main result is that oldest boys in a household are more agreeable if their next-born sibling is a girl. This effect is robust across age (10 and 16), when controlling for among others family size, and when applying corrections for multiple hypothesis tests. Agreeableness is an important trait in life as it has been shown to correlate positively among others with being employed, having a skilled job, savings, and life satisfaction.
Content may be subject to copyright.
Contents lists available at ScienceDirect
Economics of Education Review
journal homepage: www.elsevier.com/locate/econedurev
Does sibling gender affect personality traits?
Bart H.H. Golsteyn
a
, Cécile A.J. Magnée
b,
a
Department of Economics, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, Netherlands
b
CPB Netherlands Bureau for Economic Policy Analysis, P.O. Box 80510 2508 GM, The Hague, Netherlands
ARTICLE INFO
Keywords:
Sibling gender composition
Personality traits
JEL:
I2
j12, j16, j24
ABSTRACT
This paper studies whether sibling gender affects personality traits. We use the idea that if parents decide to have
a second child, it is random whether they will have a boy or a girl. Therefore, the relationship between the
second-born sibling's gender and the first sibling's personality traits is causal. We employ longitudinal data from
a large British cohort which is followed from birth onwards. The dataset includes personality traits at age 10 and
16. Our main result is that oldest boys in a household are more agreeable if their next-born sibling is a girl. This
effect is robust across age (10 and 16), when controlling for among others family size, and when applying
corrections for multiple hypothesis tests. Agreeableness is an important trait in life as it has been shown to
correlate positively among others with being employed, having a skilled job, savings, and life satisfaction.
1. Introduction
The environment in which children grow up has vital implications
for later in life outcomes. Parents, teachers, and peers determine
choices children make. Interactions between siblings are also im-
portant. Studies have shown that the number of siblings, their birth
order, and the age difference between siblings affect outcomes such as
personality traits, human capital accumulation, and wages.
1
Our paper investigates whether sibling gender affects personality
traits. As proposed by Detlefsen, Lima de Miranda, Schmidt and
Sutter (2018), siblings may affect each other because they compete for
parental attention or because they learn from each other. The effects are
theoretically hard to predict as they may go in opposite directions. On
the one hand, children may behave differently from their siblings in
order to capture more parental attention (Hertwig, Davis & Sulloway,
2002;Sulloway, 1996). This is especially pronounced if siblings are of
opposite gender (Feinberg, McHale, Crouter & Cumsille, 2003). How-
ever, they may also show similar behavior as their sibling because they
learn from each other. For example, Rust, Golombok, Hines, Johnston &
Golding (2000) shows that girls with brothers are more masculine and
boys with sisters are more feminine.
We use the 1970 British Cohort Study, a longitudinal database
consisting of approximately 18,000 children born in the UK in one week
of April 1970, to study whether the gender of the second-born sibling
influences personality traits of oldest children. The children have been
followed in 12 surveys from birth (parental survey) up to an age of 50.
The data contain information on personality traits of the children at age
10 and 16, reported by the child's mother.
One analytical complexity of studying the effect of sibling gender on
personality traits is that the decision to have a second child may be
driven by the gender of the first-born's child. Therefore, the effect of the
first-born's gender on the outcome of the second-born child may be
biased. The estimates of the second-born sibling on the oldest sibling,
however, are less concerning because once parents decide to have an-
other child, it is random whether they will have a boy or a girl.
2
The
relationship of this second-born boy or girl on the first child's outcomes
is causal. Therefore, it has become standard in the recent literature to
only focus on the effect of the second-born sibling on the oldest sibling
(see Brenøe, 2018, and Peter, Lundborg, Mikkelsen & Webbink, 2018).
We follow this strategy and study the effect of the gender of the second-
born sibling on personality traits of the oldest sibling in the household.
A second analytical issue is that when analyzing many hypotheses,
one faces the risk that results are statistically significant by chance (i.e.,
a false positive or type I error). We, therefore, apply several corrections
https://doi.org/10.1016/j.econedurev.2020.102016
Received 11 November 2019; Received in revised form 4 June 2020; Accepted 5 June 2020
Corresponding author.
E-mail addresses: b.golsteyn@maastrichtuniversity.nl (B.H.H. Golsteyn), c.a.j.magnee@cpb.nl (C.A.J. Magnée).
1
See, e.g., Barclay (2015);Bjerkedal, Kristensen, Skejeret, & Brevik (2007);Black, Devereux, & Salvanes (2007);Buckles & Munnich (2012);Golsteyn &
Magnée (2017);Hotz & Pantano (2015);Kalmijn & van de Werfhorst (2016);Rohrer, Egloff, & Schmuckle (2015);Kanazawa (2012.
2
Only from 1978 onwards, trustworthy ultrasound machines were available to determine the gender of a child during the pregnancy. Thus, parents deciding to
terminate a pregnancy in 1970 could not have based the decision on the gender of the fetus. Furthermore, Wilcox, Weinberg & Baird (1995) find no relation between
time of intercourse with respect to ovulation and sex of the resulting child and Gray, et al. (1998) find no relation between maternal hormones and sex of the child.
Economics of Education Review 77 (2020) 102016
0272-7757/ © 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/BY/4.0/).
T
for multiple hypothesis testing.
Our main results are that the gender of the sibling has implications
for personality traits. Boys with a younger sister are more agreeable.
This effect remains robust across age, when adding controls, when
correcting for potentially selective attrition, and when applying cor-
rections for multiple hypothesis testing. The implications of having a
sister may be long lasting as agreeableness is an important trait in life. It
has been shown to correlate positively among others with being em-
ployed, having a skilled job, savings, and life satisfaction. Parents,
teachers and policy makers may use this information to target the
children in need for help in these domains.
In previous studies, boys and girls have been shown to display ste-
reotypical behavior. These differences in behavior can stem from dif-
ferent parental treatment conditional on the gender of the child
(Danielsbacka, Tanskanen, Jokela & Rotkirch, 2011;McHale, Crouter &
Whiteman, 2003;Pollet, Fawcett, Buunk & Nettle, 2009), innate dif-
ferences between boys and girls, and differences in the way siblings
interact. The literature on such sibling influences has mostly focused on
birth order, age differences, and the number of siblings (references are
mentioned in footnote 1).
The effects of sibling gender have less often been studied and most
previous research has focused on the effects of sibling gender on edu-
cational attainment or wages. With respect to the effects of sibling
gender on educational attainment, Butcher and Case (1994), for in-
stance, show that women raised only with brothers receive on average
significantly more education than women raised with sisters, control-
ling for household size. These results, however, could not be replicated
by later studies. Kaestner (1997) finds that sibling sex composition had
little effect on educational achievement. Hauser and Kuo (1998) use the
Occupational Changes in a Generation Survey, the Survey of Income
and Program Participation, and the National Survey of Families and
Households and find no relationship between the gender composition of
sibships and women's educational attainment. Evidence of the effects of
sibling sex composition on later in life outcomes has also been gathered
in developing countries. Vogl (2013) examines how arranged marriage
cultivates rivalry among sisters in South Asia. During marriage search,
parents with multiple daughters rush older daughters’ marriage to have
sufficient time for her younger sisters to marry. Vice versa, older sisters
delay the younger sister's marriage. As a consequence, younger sisters
cause women to leave school earlier, to attain lower literacy levels, to
find a husband with less education and a less-skilled occupation, and to
attain a lower adult economic status.
Regarding the effects of sibling gender on wages, Brenøe (2018)
finds that women with a brother acquire more traditional gender norms
with negative consequences for their labor earnings. Rao and
Chatterjee (2018) show that the wages of men are increasing in the
proportion of male siblings, while the wages of women are insensitive
to sibling gender. Peter, Lundborg, Mikkelsen & Webbink (2018) find
that a same-sex sibling increases men's earnings and family formation
outcomes (marriage and fertility), as compared to an opposite-sex sib-
ling. The results for women are similar but the effects are smaller in
magnitude and less robust. Cools and Patacchini (2019) show that
women earn less when they have a younger brother relative to when
they have a younger sister. Interestingly, these authors furthermore find
that the lower earnings are partly driven by the fact that brothers re-
duce parents’ expectations and school monitoring of female children
while also increasing females’ propensity to engage in more tradition-
ally feminine tasks.
Our analysis contributes to this research by studying the effects of
sibling gender on personality. There are few previous papers we know
of which study closely related themes. One related analysis is a recent
discussion paper by Detlefsen et al. (2018). They study the effects of
birth order and sibling sex composition on economic preferences. They
show, firstly, that second-born children are typically less patient, more
willing to take risks, and more trusting. Secondly, second-born children
are more willing to take risks if they have same-sex siblings than in a
mixed-sex sibling case. For trust and trustworthiness, birth order effects
are larger with mixed-sex siblings than in the single-sex case. Only for
patience, siblings’ sex composition does not matter.
A second related article studies the effects of sibling gender on
cognitive and non-cognitive skills. Cyron, Schwerdt and
Viarengo (2017) find that boys benefit from having a sister in terms of
cognitive skills, learning skills, and self-control measured in kinder-
garten. They also show that these effects have faded out by the time
boys reach first grade. Girls’ cognitive and non-cognitive skills are not
affected by sibling gender. We contribute to this line of research by
analyzing a greater variety of personality traits at ages 10 and 16.
The paper proceeds as follows. Section 2 describes the data and
Section 3 explains the methods. Section 4 reports the results, and checks
the robustness of the findings. Section 5 concludes.
2. Data
We use data from the British Cohort Study (BCS70). This cohort
study follows children who were born in the same week in April 1970
up until the age of 50. In total, 12 surveys have been conducted over
this timespan.
3
Table 1 gives summary statistics on the main variables
for the full sample and for the sample used in our analyses.
2.1. Siblings
At age 5, mothers were asked to report the sex and birth date of
children born after the child followed in the surveys. We use this in-
formation to define whether the child's next-born sibling is a boy or a
girl and to determine the age gap between the first-born and second-
born child. At age 10, mothers were asked to list all members of the
household.
4
The data include the relationship to the child born in 1970
Table 1
Summary statistics.
Full sample Estimation sample
N Mean St.Dev N Mean St.Dev
Conscientiousness age 10 13,242 0 1 2782 0 1.002
Agreeableness age 10 13,153 0 1 2777 0.013 0.958
Emotional stability age 10 13,153 0 1 2768 −0.029 0.988
Conscientiousness age 16 8461 0 1 1802 0.069 0.977
Agreeableness age 16 8385 0 1 1790 0.008 0.982
Emotional stability age 16 8345 0 1 1774 −0.015 0.987
Survey child is male 13,869 0.516 0.5 2868 0.509 0.5
Of oldest child in
household, next-born
sibling is male
5095 0.524 0.499 2868 0.522 0.5
Number of children, incl.
survey child
18,751 2.181 1.197 2868 2.37 0.633
Age gap between oldest
and second child
(months)
13,058 49.648 14.955 2868 33.914 11.679
Mother is married when
child is born
17,179 0.926 0.261 2798 0.945 0.228
Note: The personality traits are standardized to a mean of zero and standard
deviation of one based on the full sample.
3
These surveys are held at the ages of 2, 5, 10, 16, 21, 26, 29, 34, 38, 42, 46
and 50 (in development).
4
See page 2 at https://cls.ucl.ac.uk/wp-content/uploads/2017/07/parental.
pdf. Since this information on family members is not available after age 10 of
the child born in 1970, siblings who were born at a later time are not included
in our analysis. This will not present any problems for our analysis since an age
gap of more than 10 years implies that these siblings interact less intensively as
they go through different life stages, and that age gaps of more than 10 years
are not very common (see, e.g., Golsteyn & Magnée 2017).
B.H.H. Golsteyn and C.A.J. Magnée Economics of Education Review 77 (2020) 102016
2
Table 2
Questions about personality traits answered by the mother at ages 10 and 16.
Conscientiousness Extraversion Agreeableness Emotional Stability
Items Cannot settle Not much liked Destroys belongings Irritable
Easily distracted Worried Fights with others Miserable/distressed
Fails to finish things Solitary Takes others’ things Requests must be met
Difficulty concentrating Afraid of new Disobedient Sullen or sulky
Fussy/over-particular Tells lies Changes mood quickly
Bullies others Outbursts of temper
interferes with others
Cronbach's alpha at age 10 0.82 0.58 0.81 0.82
Cronbach's alpha at age 16 0.81 0.57 0.78 0.84
Notes: All personality items are answered by the child's mother. At age 10, the items are scored on a scale from 1 through 100, 1 indicating ‘certainly’ and 100
indicating ‘does not apply’. At age 16, the scoring is 1 ‘certainly applies,’ 2 ‘applies somewhat,’ 3 ‘doesn't apply’ and for other traits 1 ‘not at all,’ 2 ‘just a little,’ 3
‘pretty much,’ and 4 ‘very much.’ In the analyses, we recoded the items such that a high score implies respectively more conscientiousness, more agreeableness and
more emotionally stability, and we standardize the traits to a mean of zero and a standard deviation of one.
Table 3
Relationship between gender of the next-born sibling and personality traits of the oldest child at age 10.
No controls With controls With controls and IPW With controls and IPW MHT
Effects of next-born brother on female oldest sibling at age 10
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness −0.003 0.050 0.945 1372 0.015 0.052 0.778 1209 0.015 0.052 0.778 1209
Agreeableness 0.093 0.046 0.046 1375 0.045 0.047 0.337 1212 0.045 0.048 0.343 1212
Emotional stability 0.011 0.052 0.837 1362 −0.011 0.054 0.837 1204 −0.011 0.054 0.837 1204
Effects of next-born sister on male oldest sibling at age 10
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness 0.022 0.056 0.700 1410 0.031 0.059 0.606 1274 0.031 0.059 0.606 1274
Agreeableness 0.131 0.055 0.018 1402 0.136 0.056 0.016 1265 0.136 0.057 0.017 1265 All MHT: p<0.10
Emotional stability 0.034 0.054 0.535 1406 0.044 0.056 0.431 1271 0.044 0.056 0.431 1271
Note: Each coefficient represents a separate OLS regression. The table reports OLS regressions of having a next-born brother instead of a next-born sister for girls and
having a next-born sister instead of a next-born brother for boys on various personality traits as dependent variables (displayed in the first column of the table).
Standard errors, p-values and the number of observations included in the regression are displayed next to each coefficient. All personality variables are standardized
with mean zero and standard deviation of one based on the full sample. The first set of estimates only includes a dummy variable for the gender of the next-born
sibling in the regression. The second set additionally includes controls for whether the mother was married at the time when the child was born, the socioeconomic
status of the father and the mother (dummy variables per category), and a continuous variable that measures the age gap between the child and its next-born sibling
in months with birth gaps larger than 5 years set to 5 years. The third set is similar to the second set but additionally uses inverse probability weighting. The last set is
similar to the third set but estimates whether the results hold when applying multiple hypothesis testing (MHT) corrections. We report at what level the results
remain significant using the following tests: Bonferroni, Benjamini and Hochberg (1995) and Simes (1986),Holland and Copenhaver (1988),Holm (1979),
Šidák (1968).
Table 4
Relationship between gender of the next-born sibling and personality traits of the oldest child at age 16.
No controls With controls With controls and IPW With controls and IPW MHT
Effects of next-born brother on female oldest sibling at age 16
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness 0.057 0.059 0.328 954 0.075 0.061 0.221 845 0.074 0.063 0.237 845
Agreeableness 0.085 0.054 0.120 942 0.084 0.057 0.140 835 0.081 0.058 0.165 835
Emotional stability 0.057 0.066 0.385 938 0.096 0.068 0.161 832 0.093 0.069 0.183 832
Effects of next-born sister on male oldest sibling at age 16
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness −0.110 0.071 0.124 848 −0.069 0.074 0.351 774 −0.067 0.075 0.366 774
Agreeableness 0.213 0.076 0.005 848 0.194 0.078 0.013 773 0.197 0.082 0.016 773 All MHT: p< 0.10
Emotional stability 0.114 0.067 0.088 836 0.113 0.069 0.101 762 0.116 0.070 0.098 762
Note: Each coefficient represents a separate OLS regression. The table reports OLS regressions of having a next-born brother instead of a next-born sister for girls and
having a next-born sister instead of a next-born brother for boys on various personality traits as dependent variables (displayed in the first column of the table).
Standard errors, p-values and the number of observations included in the regression are displayed next to each coefficient. All personality variables are standardized
with mean zero and standard deviation of one based on the full sample. The first set of estimates only includes a dummy variable for the gender of the next-born
sibling in the regression. The second set additionally includes controls for whether the mother was married at the time when the child was born, the socioeconomic
status of the father and the mother (dummy variables per category), and a continuous variable that measures the age gap between the child and its next-born sibling
in months with birth gaps larger than 5 years set to 5 years. The third set is similar to the second set but additionally uses inverse probability weighting. The last set is
similar to the third set but estimates whether the results hold when applying multiple hypothesis testing (MHT) corrections. We report at what level the results
remain significant using the following tests: Bonferroni, Benjamini and Hochberg (1995) and Simes (1986),Holland and Copenhaver (1988),Holm (1979),
Šidák (1968).
B.H.H. Golsteyn and C.A.J. Magnée Economics of Education Review 77 (2020) 102016
3
(e.g., brother, sister, father, etc.) and the sex of the person mentioned.
We use these answers to elicit whether the child was the oldest child in
the household and to determine the number of siblings in the house-
hold. Table 1 shows that the average household consisted of 2.2 chil-
dren including the surveyed child itself.
2.2. Personality traits
The most used taxonomy of personality is the Big Five, consisting of
openness to experiences, conscientiousness, extraversion, agreeable-
ness, and neuroticism (positively framed as emotional stability) (Costa
& McCrae, 1992;Goldberg, 1993). During the childhood of the parti-
cipating children, this taxonomy was not developed yet so standard
items to measure these traits were not included. However, Prevoo and
ter Weel (2015) show that the data contain items on personality and
behavior at age 10 and 16 from which measures capturing a child's
conscientiousness, extroversion, agreeableness, and emotional stability
can be constructed. It is not possible to capture openness to experiences
with the available items.
Table 2 shows the questions used to measure these traits. These
questions were asked at age 10 and 16 to the child's mother and mostly
refer to the child's behavior. In personality psychology it is common to
measure personality constructs both by preferences and behavior.
5
We first check whether the items indeed can be used to measure
personality traits as suggested by Prevoo and ter Weel (2015). A rule of
thumb is that items measure the same trait as long as the Eigenvalue in
a factor analysis is above one for one factor only (see Kaiser, 1960). We
find for each of the four clusters of items that the Eigenvalues of the first
factor are indeed above unity and those of the second factor are below
unity. However, the Eigenvalue of the first factor of extraversion is very
close to unity. The table also shows the Cronbach's alphas associated to
the traits. The personality psychology literature typically uses Cron-
bach's alphas as measures of reliability. Alphas of 0.7 or higher are
considered reliable (see, e.g., Kline, 2000). Using this benchmark, the
traits appear to have high reliability at all ages, with the exception of
extraversion at age 10 and 16. These findings confirm those by
Prevoo and ter Weel (2015). Since the measure of extraversion is less
reliable, we decided not to study the results for this trait in the re-
mainder of this paper. The outcomes of this paper, therefore, include
measures for conscientiousness, agreeableness and emotional stability.
In a second step, we elicit each trait by extracting the first principal
component from the set of items belonging to that trait. As shown in
Table 1, we then standardize these principle components to a mean of
zero and a standard deviation of one based on the full sample. We do so
in order to facilitate the interpretation of the size of the effects in our
regression analyses. Comparing the number of observations on our
personality trait variables in Table 1 also reveals the attrition in the
data. At age 10, around 80 percent of the original sample of children is
still in the sample. At age 16, around 62 percent is still in the sample. In
the analyses, we will study whether attrition affects our results using
inverse probability weighting.
2.3. Controls
In our regressions, we control for whether the mother was married
at the time when the child was born. Table 1 shows that around 93
percent of the mothers were married at that time. In the regressions, we
include a dummy variable for whether the mother was married.
We also control for the social class of the father and the mother of
the children we follow. These are potentially important indicators of
the environment in which the child is raised. Tables A1 and A2 display
a list of occupations related to each social class. In our analyses, we
include separate dummies for each social class.
The age difference between the surveyed child and its siblings may
also affect our estimates, e.g. competition for parental attention may be
larger when birth gaps are smaller. As mentioned above, at age 5, the
data include information on the birth year of the sibling which was born
after the surveyed child. If the first-born sibling after the surveyed child
was born later than 5 years after the surveyed child, we set the age gap
at 5 years.
2.4. Estimation sample
As we explain in the empirical strategy below, we study the effects
only of the gender of the next-born sibling on the oldest child in the
family. As a result, our estimation sample only includes children who
were born in 1970 and who are the oldest child in households with at
least two children. This implies that our sample reduces to 2868 chil-
dren. Roughly half of the sample is male. On average, the participant's
family consists of 2.4 children including the child itself. The chance that
the oldest child's next-born sibling is a brother is similar to the chance
of having a sister. The age gap between the oldest child and its next-
born sibling is around 34 months.
3. Methodology
The most important analytical complexity is that the decision to
have a second child may be driven by the gender of the first-born's
child. Therefore, the effect of the first-born's gender on the outcome of
the second-born child may be biased. The estimates of the younger on
the older siblings, however, are less concerning because once parents
decide to have another child it is random whether they will have a boy
or a girl. The relationship of this second-born boy or girl on the first
child's outcomes is causal. Therefore, it has become standard in the
recent literature to only focus on the effect of the younger on the older
sibling (see Brenøe, 2018, and Peter et al., 2018). We follow this
strategy and study the effect of the second-born sibling's gender on the
oldest sibling's personality traits. We estimate the following type of
regression models:
= + +Personality Sibling of Opposite Gender X
ii i i
In these models, the vector of personality traits P
i
includes con-
scientiousness, agreeableness, and emotional stability of the oldest
child in the household i. We run the regressions separately for boys and
girls. Our baseline estimation uses personality traits measured at age
10. In order to capture the effect on personality traits of having a next-
born sibling of the opposite gender relative to having a next-born sib-
ling of the same gender, we include Sibling of Opposite Gender
i
as our
main independent variable. The effect of this variable is captured by the
scalar δ. The error term is denoted as ɛ
i
.
In a second set of estimates, we additionally include X
i
, a vector of
control variables which includes whether the mother was married at the
time when the child was born, the socioeconomic status of the father
and the mother (dummy variables per category), and a continuous
variable that measures the age gap between the child and its next-born
sibling in months (with gaps larger than 5 years capped at 5 years).
In a third set of estimations, we check whether our results remain
robust when we account for potentially selective sample attrition using
inverse probability weights. We run auxiliary regressions of the prob-
ability to be in the sample on a set of variables including the sex of the
participant (i.e. oldest child born in 1970), whether the mother is
married and the social class of the father and mother. Using these es-
timates, we define the inverse probability weights which we include in
the regressions.
In a final set of estimations, we check whether a type I error (i.e., a
false positive) may occur because we test many hypotheses. We employ
5
For instance, the International Personality Item Pool website shows that con-
scientiousness is measured both by items that reveal preferences (“Like order”) and
also by items that ask about behavior (“Get chores done right away”). See: https://
ipip.ori.org/newBigFive5broadKey.htm#Conscientiousness.
B.H.H. Golsteyn and C.A.J. Magnée Economics of Education Review 77 (2020) 102016
4
the most commonly used multiple hypothesis tests to account for such
false positives. We test whether the results remain significant per set of
six estimates, i.e. the effects on three personality traits for boys and
three personality traits for girls at age 10.
In sensitivity analyses, we analyze whether the estimates remain
robust when including controls for the number of children in the
household, and whether the estimates remain robust when using per-
sonality traits at age 16.
4. Results
Table 3 shows the results of the effects of sibling gender on per-
sonality traits measured at age 10. Our first set of results shows that
oldest girls are more agreeable at age 10 if they have younger brothers
but when we control for other variables this effect is not robust.
We do find significant and robust effects of having a next-born sister
on agreeableness of oldest boys in the household. Boys are 0.13 stan-
dard deviations more agreeable if they have a next-born sister relative
to if they have a next-born brother. This effect remains robust when we
include other variables in the regression and when we correct for
multiple hypothesis testing. Table A3 in the Appendix shows that the
results also remain robust when we include the number of children in
the household as an additional control variable.
In Table 4 and A4, we investigate whether the results remain robust
across age. The table reports the results of the effects of sibling gender
on personality traits measured at age 16. Our main conclusion from this
table is that also at age 16, boys are more agreeable if they have a next-
born sister than if they have a next-born brother. The size of the effect
increases to around 0.20 standard deviations more agreeableness if
boys have a next-born sister.
5. Conclusions
This paper studies the effects of the gender of the sibling on per-
sonality traits. We employ a rich British data set, allowing us to follow
children from birth until age 16. Our results show that boys are more
agreeable if they have a next-born younger sister. Having a younger
sister increases boys’ agreeableness by around 0.13–0.20 standard de-
viations. We find this effect both at age 10 and at age 16.
We add to the existing literature by studying the effect of sibling
gender on a broad range of personality traits at two ages.
Cyron et al. (2017) only find positive effects on learning attitude and
self-control of boys who have a sister at the start of kindergarten, but
these effects have faded away by the time they reach first grade. In
contrast, we find significant effects of sibling gender on personality
traits at later ages, namely 10 and 16. Detlefsen et al. (2018) study
effects of sibling gender on several economic preferences of 16 year old
children, and find that second-born children are more willing to take
risk if they have a same sex sibling, and boys show more trust and
trustworthiness if they have a sister compared to girls who have a
brother. They find no effects of sibling gender on patience. While they
focus on economic preference parameters, we study effects of sibling
gender on three of the Big Five traits, and find positive effects on
agreeableness for boys if they have a next-born sister.
Personality traits correlate with important life outcomes. In Table
A6 of their article, Prevoo and ter Weel (2015) show for instance that
agreeableness correlates positively with being employed, having a
skilled job, savings and life satisfaction, and that it correlates negatively
with the likelihood to be a smoker at age 34. Although we find that
sibling gender affects agreeableness, we do not find significant relations
between sibling gender and any of these life outcomes. This may be due
to low statistical power or to other counteracting mechanisms through
which sibling gender relates to these outcomes.
Parents and policy makers may use this information to target the
children in need for help in these domains. A possibility for a policy
intervention is to better inform teachers and parents about possible
long-term risks. Future research could explore possible mechanisms,
such as gender norms, to further explain the relationship between sib-
ling gender and personality traits.
Author statement
The authors have contributed equally to this article. The authors
have both analyzed data and both have contributed by writing the ar-
ticle.
Acknowledgements
The authors thank two anonymous referees, Chris van Klaveren,
Arjan Non, Tyas Prevoo, Tom Stolp, Rolf van der Velden, Inge de Wolf
and seminar participants at Maastricht University and Free University
of Amsterdam for their valuable comments. This study was funded by
the Netherlands Organization for Scientific Research (VIDI grant 452-
16-006).
APPENDIX
Table A1
socioeconomic status father.
Types of profession
Social class I Professional occupations, including doctors, lawyers, ministers of religion, university teachers, professional engineers, etc.
Social class II Managerial and other processionals, including nurses, school teachers, company directors, etc.
Social class III NM Non-manual skilled occupations, including ship assistants, company representatives, clerical workers, draftsman, etc.
Social class III M Skilled manual workers, including mechanics, craftsmen of all types, skilled engineers, etc.
Social class IV Semi-skilled workers, including machine operators, postmen, storekeepers, porters, caretakers, etc.
Social class V Unskilled workers, including laborers, cleaners, dustmen, etc.
Other
B.H.H. Golsteyn and C.A.J. Magnée Economics of Education Review 77 (2020) 102016
5
Table A2
socioeconomic status mother.
Types of profession
Social class I & II I: Professional occupations, including doctors, lawyers, ministers of religion, university teachers, professional engineers, etc.
II: Managerial and other processionals, including nurses, school teachers, company directors, etc.
Social class III NM Non-manual skilled occupations, including ship assistants, company representatives, clerical workers, draftsman, etc.
Social class III M Skilled manual workers, including mechanics, craftsmen of all types, skilled engineers, etc.
Social class IV Semi-skilled workers, including machine operators, postmen, storekeepers, porters, caretakers, etc.
Social class V Unskilled workers, including laborers, cleaners, dustmen, etc.
Other
Housewives
Table A3
Relationship between gender of the next-born sibling and personality traits of the oldest child at age 10, controlling for the number of children in the household.
No controls With controls With controls and IPW With controls and IPW MHT
Effects of next-born brother on female oldest sibling at age 10
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness −0.001 0.050 0.982 1372 0.023 0.052 0.661 1209 0.023 0.052 0.659 1209
Agreeableness 0.079 0.046 0.090 1375 0.038 0.047 0.422 1212 0.038 0.048 0.425 1212
Emotional stability 0.009 0.052 0.867 1362 −0.006 0.054 0.911 1204 −0.006 0.054 0.911 1204
Effects of next-born sister on male oldest sibling at age 10
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness 0.017 0.057 0.759 1410 0.032 0.060 0.589 1274 0.032 0.06 0.591 1274
Agreeableness 0.099 0.055 0.070 1402 0.117 0.056 0.038 1265 0.117 0.056 0.038 1265
Emotional stability 0.007 0.054 0.899 1406 0.025 0.057 0.664 1271 0.025 0.057 0.665 1271
Note: Each coefficient represents a separate OLS regression. The table reports OLS regressions of having a next-born brother instead of a next-born sister for girls and
having a next-born sister instead of a next-born brother for boys on various personality traits as dependent variables (displayed in the first column of the table).
Standard errors, p-values and the number of observations included in the regression are displayed next to each coefficient. All personality variables are standardized
with mean zero and standard deviation of one based on the full sample. The first set of estimates includes a dummy variable for the gender of the next-born sibling in
the regression and controls for the number of children in the household (dummies). The second set additionally includes controls for whether the mother was married
at the time when the child was born, the socioeconomic status of the father and the mother (dummy variables per category), and a continuous variable that measures
the age gap between the child and its next-born sibling in months with birth gaps larger than 5 years set to 5 years. The third set is similar to the second set but
additionally uses inverse probability weighting. The last set is similar to the third set but estimates whether the results hold when applying multiple hypothesis
testing (MHT) corrections. We report at what level the results remain significant using the following tests: Bonferroni, Benjamini and Hochberg (1995) and
Simes (1986),Holland and Copenhaver (1988),Holm (1979),Šidák (1968).
Table A4
Relationship between gender of the next-born sibling and personality traits of the oldest child at age 16, controlling for the number of children in the household.
No controls With controls With controls and IPW With controls and IPW MHT
Effects of next-born brother on female oldest sibling at age 16
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness 0.052 0.059 0.379 954 0.068 0.061 0.265 845 0.067 0.062 0.280 845
Agreeableness 0.074 0.054 0.170 942 0.071 0.057 0.209 835 0.068 0.059 0.245 835
Emotional stability 0.055 0.066 0.405 938 0.098 0.068 0.152 832 0.095 0.069 0.169 832
Effects of next-born sister on male oldest sibling at age 16
Coef Se P N Coef Se P N Coef Se P N
Conscientiousness −0.114 0.072 0.114 848 −0.063 0.075 0.399 774 −0.061 0.075 0.415 774
Agreeableness 0.193 0.077 0.012 848 0.191 0.079 0.015 773 0.195 0.080 0.016 773 All MHT: p< 0.10
Emotional stability 0.112 0.067 0.098 836 0.125 0.070 0.074 762 0.128 0.070 0.069 762
Note: Each coefficient represents a separate OLS regression. The table reports OLS regressions of having a next-born brother instead of a next-born sister for girls and
having a next-born sister instead of a next-born brother for boys on various personality traits as dependent variables (displayed in the first column of the table).
Standard errors, p-values and the number of observations included in the regression are displayed next to each coefficient. All personality variables are standardized
with mean zero and standard deviation of one based on the full sample. The first set of estimates includes a dummy variable for the gender of the next-born sibling in
the regression and controls for the number of children in the household (dummies). The second set additionally includes controls for whether the mother was married
at the time when the child was born, the socioeconomic status of the father and the mother (dummy variables per category), and a continuous variable that measures
the age gap between the child and its next-born sibling in months with birth gaps larger than 5 years set to 5 years. The third set is similar to the second set but
additionally uses inverse probability weighting. The last set is similar to the third set but estimates whether the results hold when applying multiple hypothesis
testing (MHT) corrections. We report at what level the results remain significant using the following tests: Bonferroni, Benjamini and Hochberg (1995) and
Simes (1986),Holland and Copenhaver (1988),Holm (1979),Šidák (1968).
B.H.H. Golsteyn and C.A.J. Magnée Economics of Education Review 77 (2020) 102016
6
References
Barclay, K. (2015). A within-family analysis of birth order and intelligence using popu-
lation conscription data on Swedish men. Intelligence, 49, 134–143.
Benjamini, Y., & Hochberg, Y. (1995). Controlling the false discovery rate: A practical and
powerful approach to multiple testing. Journal of the Royal Statistical Society. Series B
(Methodological), 57(1), 289–300.
Bjerkedal, T., Kristensen, P., Skejeret, G., & Brevik, J. I. (2007). Intelligence test scores
and birth order among young Norwegian men (conscripts) analyzed within and be-
tween families. Intelligence, 35(6), 503–514.
Black, S., Devereux, P., & Salvanes, K. (2007). Older and wiser? birth order and iq of young
men. Boston: NBER NBER working paper 13237.
Brenøe, A. (2018). Origins of gender norms: Sibling gender composition and women’s choice of
occupation and partner. IZA Discussion Papers No. 11692. Bonn.
Buckles, K., & Munnich, E. (2012). Birth spacing and sibling outcomes. Journal of Human
Resources, 47(3), 613–642.
Butcher, K., & Case, A. (1994). The effect of sibling sex composition on women's edu-
cation and earnings. The Quarterly Journal of Economics, 109(3), 531–563.
Cools, A., & Patacchini, E. (2019). The brother earnings penalty. Labour Economics, 58,
37–51.
Costa, P. T., Jr., & McCrae, R. R. (1992). Revised neo personality inventory (NEO-PI-R) and
neo five-factor inventory (NEO-FFI) professional manual. Odessa, FL: Psychological
Assessment Resources.
Cyron, L., Schwerdt, G., & Viarengo, M. (2017). The effect of opposite sex siblings on
cognitive and noncognitive skills in early childhood. Applied Economics Letters,
24(19), 1–5.
Danielsbacka, M., Tanskanen, A. O., Jokela, M., & Rotkirch, A. (2011). Grandparental
child care in Europe: Evidence for preferential investment in more certain kin.
Evolutionary Psychology, 9(1), 3–24.
Detlefsen, L., Lima de Miranda, K., Schmidt, U., & Sutter, M. (2018). Are economic pre-
ferences shaped by the family context? The impact of birth order and siblings' sex com-
position on economic preferences. IZA Discussion Papers No. 11949. Bonn.
Feinberg, M. E., McHale, S. M., Crouter, A. C., & Cumsille, P. (2003). Sibling differ-
entiation: Sibling and parent relationship trajectories in adolescence. Child
Development, 74(5), 1261–1274.
Goldberg, L. R. (1993). The structure of phenotypic personality traits. American
Psychologist, 48, 26–34.
Golsteyn, B., & Magnée, C. (2017). Does birth spacing affect personality? Journal of
Economic Psychology, 60, 92–108.
Gray, R. H., Simpson, J. L., Bitto, A. C., Queenan, J. T., Li, C., Kambic, R. T., et al. (1998).
Sex ratio associated with timing of insemination and length of the follicular phase in
planned and unplanned pregnancies during use of natural family planning. Human
Reproduction (Oxford, England), 13(5), 1397–1400.
Hauser, R., & Kuo, H. (1998). Does the gender composition of sibships affect women's
educational attainment. The Journal of Human Resources, 33(3), 644–657.
Hertwig, R., Davis, J. N., & Sulloway, F. J. (2002). Parental investment: How an equity
motive can produce inequality. Psychological Bulletin, 128(5), 728–745.
Holland, B. S., & Copenhaver, M. D. (1988). Improved Bonferroni-type multiple testing
procedures. Psychological Bulletin, 104(1), 145–149.
Holm, S. (1979). A simple sequentially rejective multiple test procedure. Scandinavian
Journal of Statistics, 6(2), 65–70.
Hotz, V. J., & Pantano, J. (2015). Strategic parenting, birth order, and school. Journal of
Population Economics, 28(4), 911–936.
Kaestner, R. (1997). Are brothers really better? Sibling sex composition and educational
achievement revisited. The Journal of Human Resources, 32(2), 250–284.
Kaiser, H. F. (1960). The application of electronic computers to factor analysis.
Educational and Psychological Measurement, 20, 141–151.
Kalmijn, M., & van de Werfhorst, H. (2016). Sibship size and gendered resource dilution
in different societal contexts. PloS one, 11(8), Article e0160953.
Kanazawa, S. (2012). Intelligence, birth order and family size. Personality and Social
Psychology Bulletin, 38(9), 1157–1164.
Kline, P. (2000). The handbook of psychological testing (2nd ed.). London: Routledge.
McHale, S. M., Crouter, A. C., & Whiteman, S. D. (2003). The family contexts of gender
development in childhood and adolescence. Social Development, 12, 125–148.
Peter, N., Lundborg, P., Mikkelsen, S., & Webbink, D. (2018). The effect of a sibling's
gender on earnings and family formation. Labour Economics, 54, 61–78.
Pollet, T. V., Fawcett, T. W., Buunk, A. P., & Nettle, D. (2009). Sex-ratio biased towards
daughters in among lower-ranking co-wives in Rwanda. Biology Letters, 5(6),
765–768.
Prevoo, T., & ter Weel, B. (2015). The importance of early conscientiousness for socio-
economic outcomes: Evidence from the British Cohort Study. Oxford Economic Papers,
67(4), 918–948.
Rao, N., & Chatterjee, T. (2018). Sibling gender and wage differences. Applied Economics,
50(15), 1725–1745.
Rohrer, J. M., Egloff, B., & Schmuckle, S. C. (2015). Examining the effects of birth order
on personality. Proceedings of the National Academy of Sciences of the United States of
America, 112(46), 14224–14229.
Rust, J., Golombok, S., Hines, M., Johnston, K., & Golding, J. ALSPAC Study Team.
(2000). The role of brothers and sisters in the gender development of preschool
children. Journal of Experimental Child Psychology, 77(4), 292–303.
Šidák, Z. (1968). On multivariate normal probabilities of rectangles: Their dependence on
correlations. Annals of Mathematical Statistics, 39, 1425–1434.
Simes, R. J. (1986). An improved Bonferroni procedure for multiple tests of significance.
Biometrika, 73(3), 751–754.
Sulloway, F. J. (1996). Born to rebel: Birth order, family dynamics, and creative lives. New
York City: Pantheon Books.
Vogl, T. (2013). Marriage institutions and sibling competition evidence from South Asia.
The Quarterly Journal of Economics, 128(3), 1017–1072.
Wilcox, A. J., Weinberg, C. R., & Baird, D. D. (1995). Timing of sexual intercourse in
relation to ovulation—Effects on the probability of conception, survival of the
pregnancy, and sex of the baby. New England Journal of Medicine, 333(23),
1517–1521.
B.H.H. Golsteyn and C.A.J. Magnée Economics of Education Review 77 (2020) 102016
7
... Researchers now have the possibility to draw on large and nationally representative panel studies. For example, Golsteyn and Magnée (2020) made use of data from the British Cohort Study, which provides a representative picture of the British population born around 1970. Mothers rated their children's personality at both age 10 and age 16 on a number of adjectives which could be mapped onto the Big Five personality traits conscientiousness, extraversion, agreeableness, and emotional stability. ...
Article
Full-text available
Does growing up with a sister rather than a brother affect personality? In this paper, we provide a comprehensive analysis of the effects of siblings’ gender on adults’ personality, using data from 85,887 people from 12 large representative surveys covering 9 countries (the United States, the United Kingdom, the Netherlands, Germany, Switzerland, Australia, Mexico, China, and Indonesia). We investigated the personality traits risk tolerance, trust, patience, locus of control, and the Big Five. We found no meaningful causal effects of the gender of the next younger sibling, and no associations with the gender of the next older sibling. Based on high statistical power and consistent results in the overall sample and relevant subsamples, our results suggest that siblings’ gender does not systematically affect personality.
... For instance, a study by Dixon et al. (2008) suggested that in families with more than six children, the youngest three children were significantly more extroverted than the oldest. According to Golsteyn and Magnée (2020), older brothers were more agreeable when having a younger sister, as opposed to a younger brother. Bleske-Rechek and Kelley (2014), on their part, did not find birth order having an enduring effect on personality traits. ...
Article
Full-text available
Although siblings may differ considerably, the similarities between them are often an important source of emotional support in one's life and influence one's life course trajectories. In this review on the topic of sibling relationship and cross‐sibling effect interactions, we aim to encourage research interest and facilitate knowledge building. We begin our review by highlighting how the parental home may induce differentiation between siblings. Next, we illustrate the theories explaining sibling similarities and differences and discuss the factors that stimulate these. Throughout the review, we do not only highlight the complex mechanisms by which siblings imitate yet differentiate themselves, but also mutually relate to their life courses and education. New understandings of how similarities between siblings can simultaneously act as powerful influences and negative examples are provided.
... The pioneering studies focusing on children in toddlerhood (Brim, 1958;Koch, 1955) reported more gender-typical behaviour (e.g., gender-typical interests and play behaviour) (Su et al., 2009;Todd et al., 2018) in the presence of a same-sex sibling, such that children with a same-sex sibling exhibited more traditionally gender-typical behaviour than those with a sibling of the opposite sex. However, results from subsequent studies examining the relationship between sibship compositions and gender-typical behaviour have been mixed (Golsteyn and Magnée, 2020;Grotevant, 1978;Peter et al., 2018). Critically, research specifically examining whether early sibship composition influences one's cognitive strengths and career choices is lacking. ...
Article
Full-text available
Are we affected by growing up in either female or male environment? This study examined whether girls’ and boys’ academic strengths at age 16 in verbal/language school subjects, relative to technical/numerical subjects, and cognitive demands of a chosen occupation at age 35 are influenced by having same- or opposite-sex siblings. Using representative population data from Swedish registers, we extracted (Study 1) 3-sibling families (N = 17,233), focusing on the mid-born, and (Study 2) 2-sibling families (N = 118,688), focusing on the last-born child. Both studies demonstrated that individuals’ academic strengths were unaffected by sibship composition. Study 2 showed that boys with a sister tended to choose more numerically demanding occupations as compared to boys with a brother. Taken together, growing up in a more or less female or male environment, that is, having same- or opposite-sex siblings does not impact one’s tendency to be academically more or less verbally or numerically aligned.
Article
Does growing up with a sister rather than a brother affect personality? In this article, we provide a comprehensive analysis of the effects of siblings’ gender on adults’ personality, using data from 85,887 people from 12 large representative surveys covering nine countries (United States, United Kingdom, The Netherlands, Germany, Switzerland, Australia, Mexico, China, and Indonesia). We investigated the personality traits of risk tolerance, trust, patience, locus of control, and the Big Five. We found no meaningful causal effects of the gender of the next younger sibling and no associations with the gender of the next older sibling. Given the high statistical power and consistent results in the overall sample and relevant subsamples, our results suggest that siblings’ gender does not systematically affect personality.
Article
This paper sheds light on the formation process of noncognitive skills by examining the determinants of a host of personality traits. Using data from the National Survey of Midlife Development in the United States (MIDUS), for individuals in larger families (three or more children), we find having a same‐sex sibling leads to improved long‐run noncognitive skills and positive personality traits. The latter result is driven entirely by females. We examine potential mechanisms by exploring the links between parental investment and sibling interactions. The results could possibly speak to public actions to enhance child development and human capital accumulation.
Article
This paper examines the impact of sibling gender on adolescent experiences and adult labor market outcomes for a recent cohort of U.S. women. We document an earnings penalty from the presence of a younger brother (relative to a younger sister), finding that a next-youngest brother reduces adult earnings by about 7%. Using rich data on parent-child interactions, parents’ expectations, disruptive behaviors, and adult outcomes, we provide a first step at examining the mechanisms behind this result. We find that brothers reduce parents’ expectations and school monitoring of female children while also increasing females’ propensity to engage in more traditionally feminine tasks. These factors help explain a portion of the labor market penalty from brothers.
Article
The common approach to the multiplicity problem calls for controlling the familywise error rate (FWER). This approach, though, has faults, and we point out a few. A different approach to problems of multiple significance testing is presented. It calls for controlling the expected proportion of falsely rejected hypotheses — the false discovery rate. This error rate is equivalent to the FWER when all hypotheses are true but is smaller otherwise. Therefore, in problems where the control of the false discovery rate rather than that of the FWER is desired, there is potential for a gain in power. A simple sequential Bonferronitype procedure is proved to control the false discovery rate for independent test statistics, and a simulation study shows that the gain in power is substantial. The use of the new procedure and the appropriateness of the criterion are illustrated with examples.
Article
I examine how one central aspect of the childhood family environment—sibling gender composition—affects women's gender conformity, measured through their choice of occupation and partner. Using Danish administrative data, I causally estimate the effect of having a second-born brother relative to a sister for first-born women. The results show that women with a brother acquire more traditional gender norms with negative consequences for their labor earnings. I provide evidence of increased gender-specialized parenting in families with mixed-sex children, suggesting a stronger transmission of traditional gender norms. Finally, I find indications of persistent effects to the next generation of girls.
Article
We examine how the gender of a sibling affects labor market outcomes and family formation. Identification is complicated by parental preferences: if parents prefer certain sex compositions over others, children’ s gender affects not only the outcomes of other children but also the existence of potential additional children. We employ two empirical strategies that both address this problem. First, we use a large sample of singletons to estimate whether first-borns are affected by the gender of their second-born sibling. Second, we look at a sample of dizygotic (i.e. non-identical) twins. We find that a same-sex sibling increases men's earnings and family formation outcomes (marriage and fertility), as compared to an opposite-sex sibling. The results for women are similar but the effects are smaller in magnitude and less robust. We argue that the income result for men could be driven by competition between brothers, as we find that men with brothers choose higher paying occupations. For women, we find suggestive evidence that the income premium may come partly from lower unemployment, which could be due to shared job search networks. The effects on family formation might stem from differential parental treatment for men, and from competition between sisters for women.
Article
The equity heuristic is a decision rule specifying that parents should attempt to subdivide resources more or less equally among their children. This investment rule coincides with the prescription from optimality models in economics and biology in cases in which expected future return for each offspring is equal. In this article, the authors present a counterintuitive implication of the equity heuristic: Whereas an equity motive produces a fair distribution at any given point in time, it yields a cumulative distribution of investments that is unequal. The authors test this analytical observation against evidence reported in studies exploring parental investment and show how the equity heuristic can provide an explanation of why the literature reports a diversity of birth order effects with respect to parental resource allocation.
Article
Family influences on economic performance are investigated. In particular, sibship sex composition is related to hourly wages using data from the National Longitudinal Survey of Youth 1979. The wages of men are increasing in the proportion of siblings who are brothers, but the wages of women are insensitive to sibling gender. Nonwage outcomes are generally unaffected. Contrasts by age structure and demographic group are also presented. The analysis addresses econometric challenges like the endogeneity of fertility and selection into the workforce. In addition, mechanisms such as labour market interactions, human capital investment and role model effects are documented. A questionnaire on job search indicates a same-gender bias in the use of brothers and sisters in obtaining employment. Developmental and psychological assessments suggest that brothers may be associated with worse childhood home environments and more traditional family attitudes among women. The findings are policy relevant and contribute to an understanding of gender differences and earnings inequality.
Article
This paper studies the causal effect of birth spacing (i.e., the age difference between siblings) on personality traits. We use longitudinal data from a large British cohort which has been followed from birth until age 42. Following earlier studies, we employ miscarriages between the first and second child as an instrument for birth spacing. The results show that a larger age gap between siblings negatively affects personality traits of the youngest child in two-child households. This result sheds a first light on the causal effects of birth spacing on personality traits.
Article
We investigate the effect of having opposite sex siblings on cognitive and noncognitive skills of children in the United States at the onset of formal education. Our identification strategy rests on the assumption that, conditional on covariates, the sibling sex composition of the two firstborn children in a family is arguably exogenous. With regard to cognitive skills, learning skills and self-control measured in kindergarten, we find that boys benefit from having a sister, while there is no effect for girls. We also find evidence for the effect fading out as early as first grade.