Advances in Applied Sociology
2013. Vol.3, No.2, 137-141
Published Online June 2013 in SciRes (http://www.scirp.org/journal/aasoci) http://dx.doi.org/10.4236/aasoci.2013.32018
Copyright © 2013 SciRe s . 137
Gender and Overconfidence: Effects of Context, Gendered
Stereotypes, and Peer Group
Niklas Jakobsson1, Minna Levin2, Andreas Kotsadam3
1Norwegian Social Research (N OVA), Oslo, Norway
2Schools for the Future , San Salvador, El Salvador
3Norwegian Social Research (N OVA), Oslo, Norway
Email: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org
Received February 6th, 2013; revised March 10th, 2013; accepted March 18th, 2013
Copyright © 2013 Niklas Jakobsson et al. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited.
Research on Swedish school children has found that boys tend to be overconfident about their grades in
mathematics, while girls tend to be underconfident. We find similar results for El Salvadorian children.
Mathematics is considered a masculine task and we show that these findings do not carry over to a gender
neutral task (social science), where both sexes tend to be overconfident. We find that girls in a single-sex
school are more underconfident in their mathematics abilities than girls in a co-ed school, which may
suggest that gender stereotypes become reinforced in single-sex environments.
Keywords: Gender, Overconfidence, Peer Group, Stereotype
Previous research indicates that people are generally over-
confident in diverse areas as car-driving, investment decisions,
entrepreneurial behavior, running, stock market forecasts, an-
swering quiz questions, and solving fictitious mathematical
problems (e.g., Beckmann & Menkhoff, 2008; Croson &
Gneezy, 2009; Deaves, 2010; Koellinger et al., 2007; Svensson,
1981). And while both men and women are overconfident, men
are generally more so than women (Estes & Jinos, 1988; Fellner
& Maciejovsky, 2007; Soll & Klayman, 2004; Niederle &
Vesterlund, 2007). Dahlbom et al. (2010) find that Swedish
sch oolboys tend to be overconfident with respect to their mat he-
matics performance, while girls tend to be underconfident.
Differences in confidence are likely to translate into differ-
ences in outcomes, educational choices, and labor market seg-
regation. Dahlbom et al. (2010) argue that gender differences in
confidence may perpetuate segregated labor markets, by means
of self-selection. An indirect effect of confidence differences
may also be at work via competition decisions and performance.
Niederle and Vesterlund (2007) show that male overconfidence
is a key factor in explaining gender differences in willingness to
compete and in selection of compensation schemes, and they
argue that this may help explain the underrepresentation of
women in top-level company positions. Palomino et al. (2010)
model how male overconfidence leads to gender wage differ-
ences even with equal productivity and equal compensation
policies since more men apply for high paid jobs and exert
In this paper, we study the gender gap in confidence among
school children. For comparability with Dahlbom et al. (2010),
we conduct a study with a similar design, i.e., we ask students
about their expected test results before a test and compare with
the actual results, yet our study extends the results in Dahlbom
et al. (2010) along a number of important dimensions.
First of all, our design allows us to test for peer group effects
by including not only a mixed school but also an all-girls
school. Several studies have shown that men often outperform
women in competitions, even when they perform equally well
in a non-competitive setting (e.g., Gneezy et al., 2003; Gneezy
& Rustichini, 2004). Niederle & Vesterlund (2007) show that
there is a gender difference in selection into competition, but
the response to competition and the selection into it may, how-
ever, vary with the task used or with the gender composition of
the groups (Croson & Gneezy, 2009). Ortmann and Tichy
(1999) look at prisoner’s dilemma games and find men to act
the same in mixed groups as in men-only groups. Women, on
the other hand, were more cooperative in the mixed-sex groups.
Gneezy and Rustichini (2004) find that competition enhances
the performance of males but not of females in a short distance
running race in an Israeli elementary school. The gender com-
position also had an effect: When girls competed against girls,
their performance was worse compared to when running alone.
In the mixed races did the girls performed less well than when
running alone but better than when competing against only girls.
For boys, there was no statistically significant difference be-
tween the performance in mixed races and boys-only races and
their performance was better compared to when running alone.
Booth and Nolen (2012a, 2012b) find that girls in single-sex
schools compete more and are less risk averse than girls from
co-ed schools in Great Britain, suggesting that these traits are
not only in inherent but may also depend on the social setting.
Our study is the first to test if the gender differences in confi-
dence varies between single-sex and mixed sex environments.
Secondly, in addition to performance in mathematics, we
also consider overconfidence regarding performance in the
N. JAKOBSSON ET AL.
social sciences. This addition is important since, as Niederle
and Vesterlund (2007) point out, differences in overconfidence
are task dependent and gender differences have generally been
found in masculine tasks. Meier-Pesti and Penz (2008) argue
that risk taking is perceived as a masculine characteristic and
that previous results on the gender differences in risk taking
stems from this fact. They move on to show that gender differ-
ences in risk taking decreased once they controlled for mascu-
linity and that activating the cognitive schema of male sex role
stereotype by gender priming increased risk taking. Lundeberg
et al. (1994) find men to be more confident than women re-
garding exam questions related to math, but not regarding exam
questions related to learning, memory, or experimental design.
Beyer (1990) and Beyer and Bowden (1997) show that gender
differences in the accuracy of self-perceptions are significant
for masculine tasks (where men are generally overconfident and
women underconfident), while no differences were found for
feminine or neutral tasks. Finally, Günther et al. (2010) show
that women are less competitive than men in male tasks, but
more competitive in the studied female task; no difference is
found for gender neutral tasks. Hence, it is crucial to distinguish
between masculine and non-masculine tasks. If both sexes
agree that members of one sex are better at a task, it is said to
be gender typed. It is important to note that the categorization
need not be supported by facts, only by stereotypes, so that
when Gneezy and Rustichini (2004) contend that there is no
gender difference in performance with respect to running short
races, there might still be stereotypical perceptions of the task
nonetheless. Mathematics is a typical example of a mascu-
line-typed task (e.g., Beyer, 1990; Beyer & Bowden, 1997;
Janman, 1987; Mura, 1987; Tiedemann, 2000), that is not sup-
ported by actual differences in results at lower levels or at
young ages (Dahlbom et al., 2010; Niederle & Vesterlund, 2007;
our data also shows that girls outperform boys on the mathe-
matics test). Social science, on the other hand, is generally con-
sidered gender neutral and by including it in addition to
mathematics in our study, we are able to investigate whether
the results in Dahlbom et al. (2010) generalize to non-mascu-
Finally, by following the design of Dahlbom et al. (2010) but
applying it to another country, we are able to test for gender
differences in overconfidence across countries. Previous confi-
dence research has been more occupied with individual rather
than social psychology, and we aim to fill this gap by introduc-
ing context as a crucial component of the analysis. Since we are
looking specifically at gender differences, the societal level of
gender equality is likely to be important, especially if gender
roles are partly a product of childhood socialization. For in-
stance, the gender differences between Israeli boys and girls in
running race performance found by Gneezy and Rustichini
(2004) were not found in a similar study on Swedish school-
children conducted by Dreber et al. (2011), and Johansson-
Stenman and Nordblom (2010) find no gender differences in
overconfidence in an economics exam in Sweden. Guiso et al.
(2008) studied gender differences in mathematics and reading
test scores across countries. On average, girls performed worse
on the math test and better on the reading test than boys, yet the
results vary by country. In particular, in countries with greater
gender equality (as measured by the World Economic Forum’s
Gender Gap Index), the differences in mathematics disappear or
even get reversed while the gap in reading increases. Our study
is conducted in El Salvador, a less gender equal country than
Sweden (which was used by Dahlbom et al., 2010). The Global
Gender Gap Report 2012 ranks Sweden as the fourth most
gender equal country in the world; El Salvador ranks 94th
(Hausmann, Tyson, & Zahidi, 2012).
Croson and Gneezy (2009) review economic and psycho-
logical research on gender differences in experiments and find
that women’s social preferences are more context specific than
those of men, and a potential reason for this is said to be
women’s higher sensitivity to social cues. Recent experimental
research has highlighted the importance of social structure.
Gneezy et al. (2009) contrast the results from the same experi-
ment across cultures. They look at the patriarchal Maasai soci-
ety in Tanzania and a matrilineal Khasi society (offspring be-
long to the mother’s group after birth) in India and find that
men in the patriarchal society choose to compete twice as often
as women, whereas women choose to compete more often than
men in the matrilineal society. In a similar vein, Andersen et al.
(2008) conducted a public goods experiment in three different
Indian societies, one matrilineal and two patriarchal, and found
that fewer individuals free-ride and more is spent on the public
good in the matrilineal society. By following the design used in
Dahlbom et al. (2010), we can examine the gender differences
in math confidence between countries and hence shed light on
the role of different contexts.
One aim of this study is therefore to find out whether Dahl-
bom et al.’s (2010) results are generalizable to youth in less
gender equal societies. Another aim is to investigate differences
between the highly gendered topic of mathematics and the less
gendered topic of social science. Most importantly, though, we
aim to find out whether girls in single-sex schools differ from
girls in co-ed schools in terms of confidence, as found regard-
ing risk and competition behavior in Great Britain (Booth &
Nolan, 2012a, 2012b).
Data Description and Method
Our sample consists of 129 students aged 15 - 16 from two
schools in Santa Tecla in El Salvador. In total, 66 students
come from a co-ed school (34 boys and 32 girls) and 63 stu-
dents come from an all-girls school. Both schools are public
schools and free of charge. All children come from a similar
social background (poor) and all parents can register their kids
at either schoo l.
The students were asked what grades (from 1 to 10, where 10
is the highest) they expected to get on two subsequent tests—
one in mathematics and one in social science. What we here
call social science is a subject called “sociales” which is a com-
bination of social science and language. The questions were
“What grade do you expect to get on the upcoming exam in
mathematics?” and “What grade do you expect to get on the
upcoming exam in social science?” We also have the actual test
results for each student.
For statistical testing we will use the Wilcoxon signed rank
sum test, which is a non-parametric version of a paired samples
t-test. We use this test statistic since we use ordinal and not
necessarily normally distributed data.
Overconfidence in Math and Social Science
We consider the differences between boys and girls for the
total sample and compare them to those found by Dahlbom et al.
(2010). Table 1 presents the mean beliefs and results for the
Copyright © 2013 SciRe s .
N. JAKOBSSON ET AL.
Mean beliefs and actual results in the total sample.
Belief math Result math
science Result social
Note: Mean values and s tandard deviations in parentheses.
total sample, for boys and for girls, respectively. Expected
grades differ from actual grades. Both girls and boys overesti-
mate their social science performance (statistically significant
at the 5 percent level for girls and the 1 percent level for boys,
using a Wilcoxon signed rank test). Throughout the paper, the
reported statistical significance refers to Wilcoxon signed rank
tests unless stated otherwise. Regarding math, girls underesti-
mate their performance (statistically significant at the 10 per-
cent level), while boys overestimate theirs (statistically signifi-
cant at the 1 percent level). The difference between girls and
boys in confidence is also statistically significant (at the 1 per-
cent level in a Wilcoxon rank sum test) for both mathematics
and social science.
Regarding mathematics performance, we thereby find the
same results as the Swedish study (Dahlbom et al., 2010),
where girls tended to be underconfident and boys overconfident.
With respect to social science, on the other hand, both girls and
boys are generally overconfident, but boys more so than girls.
This is in line with research on confidence in other areas of life
(e.g., Estes & Jinos, 1988; Soll & Klayman, 2004; Niederle &
Vesterlund, 2007). Thus, the results found in Dahlbom et al.
(2010) for mathematics seem to generalize even to less gender
equal countries like El Salvador. It is also interesting to note
that not only do the results differ by task, the direction of con-
fidence bias is even reversed for girls; i.e., girls are overconfi-
dent in the gender neutral typed task, although less so than men,
while they are underconfident in the masculine typed task.
Mixed Schools and Single-Sex Schools
Earlier research suggests that differences in confidence be-
tween girls and boys may depend on peer groups. Booth and
Nolen (2012a, 2012b) find that girls in single-sex schools
compete more and are less risk averse than girls from mixed
schools. An important question is whether the gendered peer
group effect is salient also for confidence, and whether their
result generalizes to outside Great Britain. Thus, we will inves-
tigate whether there are any differences between girls from
single-sex schools and girls from mixed schools. More specifi-
cally, if the results regarding risk aversion and competition
translate directly to confidence, we would expect to find that
girls in the all-girls school are more overconfident with respect
to social science and less underconfident with respect to math,
than are girls in the co-ed school. On the other hand, if the
gender typedness of a task gets reinforced in single-sex envi-
ronments, we may find that girls in the all-girls school are more
underconfident regarding their mathematics abilities than are
girls in the mixed school.
Table 2 presents the mean expectations and results for all
Mean beliefs and actual results for girls in the mixed and single-sex
Belief mathResult math
science Result social
Note: Mean values and s tandard deviation in parentheses.
girls, girls in the mixed school, and girls in the single-sex
school, respectively. The results shown in the first row are the
ones presented also in Table 1. In the second row, the results
for girls in mixed school are presented. These girls are over-
confident, not only regarding social science, but also regarding
mathematics (statistically significant at the 1 percent level for
both social science and math). Girls in the single-sex school are
underconfident regarding their math performance (statistically
significant at the 1 percent level), while regarding their social
science abilities, they believe they will get a slightly higher
score than they actually do, although this difference is not sta-
tistically significant. The difference between girls from the two
types of schools is statistically significant at 1 percent for math
performance and at 5 percent for social science performance
(using the Wilcoxon rank sum test).
Thus, our results indicate that girls from the single-sex
school are less like boys in terms of confidence, as compared to
girls from mixed schools. This is contrary to the results we
would have obtained had the results regarding competition and
risk taking (Booth & Nolen, 2012a, 2012b), where girls in sin-
gle-sex schools are more similar to boys than are girls in mixed
schools, been directly transferable. Since we find that girls in
the single-sex school tend to be underconfident while those in
mixed schools tend to be overconfident in the masculine typed
task, the results may suggest that single sex environments rein-
force stereotypes of gender typedness.
Confidence has been widely studied in psychology and eco-
nomics. Confidence is important for aspirations, motivation,
and preferences for challenging tasks, and may affect career
choices and education (Beyer & Bowden, 1997; Dahlbom et al.,
2010). Previous research has found that people generally are
overconfident in diverse areas as car-driving, investment deci-
sions, running, stock market forecasts, answering quiz ques-
tions, and solving fictitious mathematical problems. And while
both men and women are overconfident, men are generally
more so than women. Previous confidence research has been
more occupied with individual rather than social psychology,
and we aim to fill this gap by introducing context as a crucial
component of the analysis. We conducted a survey where high
school students from a co-ed school and an all-girls school were
asked what grades they thought they would get on two subse-
quent tests—one in mathematics and one in social science.
Their expectations were then compared to their actual grades.
In line with the Swedish results from Dahlbom et al. (2010),
this article shows that boys tend to be overconfident in their
Copyright © 2013 SciRe s . 139
N. JAKOBSSON ET AL.
mathematics skills, while girls are underconfident. The results
regarding mathematics therefore seem to be generalizable
across cultures. Mathematics is regarded as a masculine typed
task while social science is regarded as gender neutral. The
present study shows that both girls and boys are overconfident
in their social science abilities, but girls less so than boys. We
thereby conclude that gender typedness of task does matter.
This is especially true for girls, for whom the confidence bias is
reversed across tasks. That is, girls are overconfident in the
gender neutral typed task, although less so than boys, while
they are underconfident in the masculine typed task. Further-
more, we show that girls from the all-girls school are more
underconfident in their mathematics abilities than girls in the
co-ed school. This contrasts results found for competition and
risk taking (Booth & Nolen, 2012a, 2012b), where girls in sin-
gle-sex schools are more competitive and risk taking than are
girls in mixed schools. Our finding that girls from the sin-
gle-sex school are underconfident while mixed school girls are
overconfident in the masculine typed task may suggest that
single-sex environments reinforce stereotypes of gender typed-
ness. On the other hand, since girls from the single-sex school
are less confident than girls in the mixed school in both tasks, it
may be a matter of an effect on self-confidence in general.
Thus, single sex schooling seems to affect self-confidence
differently than it affects risk taking and competitive behavior.
It may, however, also be the case that the effects differ among
countries. The results may also be driven by selection into
schools based on unobserved characteristics. Both schools are
public schools (free of charge) in Santa Tecla in El Salvador.
All children come from very poor conditions and parents are
free to register their kids at either school. We may have a prob-
lem if attendance in one of the schools is correlated with confi-
dence. If so, we cannot identify the effect of being in an
all-girls school or a co-ed school. Another potential problem is
that the children in the co-ed school answered the confidence
questions the day before their tests, while the children in the
all-girls school answered the questions two weeks before the
test. If for example time inconsistency is of importance, this
may be what drives the results. Furthermore, it is interesting to
note that the differences, especially between the different
schools, are driven by differences in results rather than differ-
ences in expectations. Taken together with the result in Hoxby
(2000) that both males and females perform better in mathe-
matics in classes with more females, this may imply that sin-
-gle-sex environments affect results without affecting confi-
dence. More research, from different contexts, is definitely
warranted to shed light on these issues.
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