Conformity to Peer Pressure in Preschool Children
Daniel B. M. Haun
Max Planck Institute for Evolutionary Anthropology;
Max Planck Institute for Psycholinguistics;
and University of Portsmouth
Michael Tomasello
Max Planck Institute for
Evolutionary Anthropology
Both adults and adolescents often conform their behavior and opinions to peer groups, even when they themselves
know better. The current study investigated this phenomenon in 24 groups of 4 children between 4;2
and 4;9 years of age. Children often made their judgments conform to those of 3 peers, who had made obviously
erroneous but unanimous public judgments right before them. A follow-up study with 18 groups of 4
children between 4;0 and 4;6 years of age revealed that children did not change their ‘‘real’’ judgment of the
situation, but only their public expression of it. Preschool children are subject to peer pressure, indicating sensitivity
to peers as a primary social reference group already during the preschool years.
Humans conform. With little or no reﬂection, we
adopt many functionless and ever-changing fads
and fashions of those around us. We not only conform
to arbitrary fashions but also conform to
majority opinion when we know better ourselves.
The experimental demonstration of individual’s
knowingly giving false responses to conform to an
erroneous majority has sparked decades of scientiﬁc
discourse and wonder (Asch, 1956; Cialdini &
Goldstein, 2004). To contrast this situation with one
in which there is simple conformity to a majority
(e.g., in choosing one style of shirt over another) we
call it ‘‘strong conformity.’’ Despite its negative
connotation in much intellectual discourse, conformity,
especially strong conformity, serves a crucially
important function in the transmission of
human culture by promoting quick and stable
in-group uniformity, which then stabilizes
between-group cultural diversity over time (Henrich
& Boyd, 1998; Henrich & Henrich, 2007).
Genetically similar people, living in physically
similar environments, demonstrate dramatic differences
in their traditions, behavior, and cognition
(e.g., Dehaene, Izard, Spelke, & Pica, 2008; Goldstein,
Davidoff, & Roberson, 2009; Haun & Rapold,
2009; Haun, Rapold, Call, Janzen, & Levinson, 2006;
Majid, Bowerman, Kita, Haun, & Levinson, 2004;
Malinowski, 1929; Segall, Campbell, & Herskovits,
1963). These differences are maintained through
time despite factors such as migration and intermarriage,
which constantly mix individuals
between neighboring groups (Barth, 1969). Given a
long enough time span, the mixing of languages,
traditions, and knowledge should cause most differences
between groups to disappear, while, in
fact, they do not. Instead of diminishing, crossgroup
differences in humans are maintained by a
complex set of sociopsychological mechanisms
including, importantly, a strong tendency to conform
to the behavior of those in one’s group (Henrich
& Boyd, 1998).
The behavioral repertoire of one’s group is
acquired from a young age. Children quickly and
strategically learn skills by observing adult models
(Gergely, Bekkering, & Kiraly, 2002; Schwier, van
Maanen, Carpenter, & Tomasello, 2006; Tomasello,
1999). When confronted with multiple models presenting
conﬂicting information, preschool children
tend to trust those adults they have seen as conformists
rather than dissenters (Corriveau, Fusaro,
& Harris, 2009). When confronted with adult
models presenting information that stands in conﬂict
with their own, preschoolers will often sucWe
are indebted to Nadja Richter for her extraordinary coordination
and support during all stages of this project. We are
grateful to Constanze Weiske, Juliane Dauksch, Christiane Markmann,
Martina Wittig, Stefanie Voigt, Kristin Schotte, and Franziska
Kro¨bel for their assistance and the children, caretakers and
kindergarten teachers for their support. We also extend thanks
to Hannes Rakoczy, Jonathan Beier, Bridget Waller, Katja Liebal
and Yvonne Rekers for guidance. This research was funded by
the Max Planck Society.
Correspondence concerning this article should be addressed to
Daniel Haun, Max Planck Institute for Evolutionary Anthropology,
Research Group for Comparative Cognitive Anthropology,
Deutscher Platz 6, 04103 Leipzig, Germany. Electronic mail may
be sent to haun@eva.mpg.de.
Child Development, November ⁄ December 2011, Volume 82, Number 6, Pages 1759–1767
Ó 2011 The Authors
Child Development Ó 2011 Society for Research in Child Development, Inc.
All rights reserved. 0009-3920/2011/8206-0005
DOI: 10.1111/j.1467-8624.2011.01666.x
cumb to the adult’s point of view (Ma & Ganea,
2009) as well as to a majority of adults (Corriveau
& Harris, 2010). In summary, already young children
are sensitive to information provided by
adults, strategically considering motivations, social
context, and authority. Comparatively little is
known about children’s strategies when confronted
with information provided by peers. This is important
because conformity to adults may rest, ultimately,
on fear of punishment. Strong conformity
to peers—reversing one’s own behavior or opinion
under peer group pressure even when one knows
better—has been documented in school-age children
and adolescents (Berndt, 1979; Bishop & Beckman,
1971; Costanzo & Shaw, 1966). Two studies
previously attempted to test strong conformity in
children below 5 years of age (Corriveau & Harris,
2010; Walker & Andrade, 1996). Corriveau and
Harris (2010) tested preschoolers’ susceptibility to
the unanimous but erroneous opinion of a televised
majority of adults. They report that children sometimes
defer to the adult majority unless the children’s
response is of immediate practical relevance.
It remains unclear whether preschoolers in this situation
react to adults’ authority only (Ma & Ganea,
2009). This confound with obedience is absent in a
slightly older study by Walker and Andrade (1996)
using a set of same-age stooges. They report comparable
levels of conform responses. Interestingly,
they report a decline in conform responses between
3 and 17 years of age. However, partly due to the
difﬁculty of instructing peers as stooges, this study
had only two critical trials in the preschool-age
group and so did not allow for a detailed analysis
of children’s behavior. Additionally, both studies
do not allow interpretations of preschooler’s underlying
motivations: have the children actually changed
their minds as a result of the majority opinion,
or are they only acting as if they have to mollify the
others.
In the present study, we focused on strong conformity
to a peer group in preschoolers. We might
think of conformity of this type as signaling the origins
of peers as a primary social reference group
for young children. The age at which we should
expect strong conformity to peer pressure is not
clear. Children only start to understand and produce
self-presentational behaviors among peers
from about the age of 8 onward (Banerjee, 2002).
However, it is conceivable that they are sensitive to
peer pressure at an earlier age.
In this study, we therefore employed a paradigm
very similar to that of the original Asch (1956)
experiments, but with 4-year-old children. In the
crucial experimental condition, an individual subject
was asked to make an ‘‘easy’’ perceptual judgment
immediately after three peers had announced
a clearly wrong but unanimous judgment in that
same task. In a second study we sought to establish
if children would submit to peer pressure equally
readily if their own judgments were given publicly
in front of the peers or privately to the experimenter
only—thus determining whether the peers
inﬂuenced their ‘‘real’’ opinion, or only their public
expression of it.
Experiment 1
In the ﬁrst study, we created an experimental situation
as comparable as possible to Asch’s (1956) original
experimental design. Subjects were 4-year-old
children, and the reference group was three other
4-year-old children.
Method
Participants. A total of 96 four-year-old children
(mean age = 53 months, SD = 1.21 months, range =
50–57 months) participated in this study. Children
were tested in 24 gender-mixed groups of 4 children
each. Every group consisted of 3 children
forming a unanimous majority and one child in the
minority position (‘‘minority child’’). All children
in a group went to the same kindergarten (where
they were tested) and knew each other before the
study. Among the 24 minority children there were
an equal number of boys and girls. Where possible,
the groups were gender balanced (13⁄24). In all
other groups, the child in the gender minority was
never the minority child. All children were
recruited from local kindergartens, were native
German speakers of normal ability range, and came
from mixed socioeconomic backgrounds. As too
many errors might make the majority appear nonunanimous,
we excluded all groups in which the
majority children made signiﬁcantly more mistakes
than could be expected based on the average baseline
performance on the point before trials (see the
Procedure). Given approximately 5% errors in the
point before task (appr. 15% for all three majority
children taken together), the signiﬁcance level is
crossed at 10 errors (one-sample t test against 15%:
t = 2.1, df = 29, p = .045). In consequence, two
groups were excluded due to more than one third
nonunanimous majority responses. Furthermore,
two additional groups were excluded due to experimenter
error. Children were free to choose not to
1760 Haun and Tomasello
participate at all times (one quit). The samples
reported above are the ﬁnal numbers after exclu-
sions.
Materials. We created picture books in which
each double page contained four replications of the
same cartoon animal in three different sizes (large
= 4.5 · 4.5 cm, middle = 3.15 · 3.15 cm, small =
1.8 · 1.8 cm). Three animals (large, middle, and
small in pseudorandomized order) were printed on
the left-hand page, one animal (pseudorandomly
either large, middle, or small) was printed on the
right-hand page (Figure 1B). Each book contained
30 double pages with a different kind of animal on
each. In each session, three of the books were identical
(majority books), whereas one book was identical
in the order of animals across pages but
deviated on some trials as to which size was
printed on the right-hand side (minority books). In
this way we create a minority facing a unanimous
majority of three peers. To create four small booths
for the children to sit in we used two intersecting
wooden boards (85 · 90 cm each; see Figure 1A).
Each booth was color coded (orange, green, blue,
red) and ﬁtted with a color-matching pillow and a
small alien-shaped bedside lamp. Color distribution
across social status positions was counterbalanced
across subjects. All behavior was recorded by four
dv-camcorders (one for each child) on a four-way
split screen.
Procedure. Instruction Session 1: Children sat in
a row facing the Experimenter (E). E showed the
children warm-up picture books with six sets of
animals. During this warm-up period E established
the three left-hand animals on each double page as
a family picture (large = daddy, middle = mommy,
small = baby). The right side of the same double
page pictured a replication of one of the three
animals. E explained that one of the three family
members had run over to the right-hand side. The
children were asked to identify this individual picture
as daddy, mommy, or baby. Children were
probed individually to ensure understanding. Then
children were asked to identify the single individual
by silently pointing to the corresponding individual
in the family picture.
Next, E assigned one of the children to be the
target child using the following procedure. The
gender of the target child and the color of its booth
(e.g., red) were determined prior to the session.
After the warm-up, E ﬁrst instructed the two children
who were not of the predetermined gender to
sit, for example, in the blue and orange booths.
Then she instructed the two remaining children to
choose one of the leftover booths. The child ending
up in the red booth was the target child (minority).
The other children formed the majority. From this
point on, E only ever gave neutral feedback to children’s
responses.
Point Before: Each child was asked in succession
to silently point to the animal in the family picture
corresponding in size to the single individual on
the opposite page. The target child always
responded last. This block lasted six trials. The purpose
of the point before trials was to determine the
basic performance level of children in this relative
size judgment task.
Instruction Session 2: After completing the six
pointing trials, all children were asked to leave
their booths and sit in a row facing E. They were
now instructed to identify the single individual
by saying out loud ‘‘Papa,’’ ‘‘Mama,’’ or ‘‘Baby’’
(daddy, mommy, baby). Further, children were told
that they were only allowed to talk when their
lamp was switched on. The lamp was meant to
ensure that children do not speak between trials.
Then children were sent back in their booths.
Speak trials: Each group completed 18 speak trials.
On any trial, children were asked individually
in succession to say out loud the family member,
which had moved to the opposite page. The target
child always responded last. On 12 of these trials
the minority book deviated from the majority books
(conﬂict trials). On the other 6 trials (Trials 1, 2, 3,
8, 13, and 18) all four books were identical (no conﬂict
trials). This trial order replicates exactly Asch’s
original design (Asch, 1956).
Figure 1. (A) Experimental setup from a birds-eye perspective. Light bulbs identify the location of the lamps. (B) Example of a stimulus
from the relative size judgment task.
Peer Pressure in Preschool Children 1761
Point After: Finally, the children received six
more silent pointing trials. Children were again
asked individually in succession to silently point to
the animal in the family picture corresponding in
size to the single individual on the opposite page.
The target child always responded last.
Debrieﬁng: Finally, after children had been told
that the experiment had ended, E, in a surprised
manner, stated that she had accidentally mixed up
one of the books. She then asked if anyone had
noticed something odd about his or her book. Then
she demonstrated for everyone to see that one of
the books was different from the others and apologized
for her mistake. With this procedure, we
attempted to prevent any negative consequences
for the minority child’s self-esteem or reputation.
Data scoring and analysis. We videotaped all
trials. We scored the responses (pointing and
speaking) from videotapes and⁄or in situ notes. The
pointing trials serve as an ability check, probing
children’s individual performance on the task at
the beginning and end of the session. We further
planned to test whether children’s performance differed
between the speak–no conﬂict and speak–
conﬂict trials indicating an effect of peer pressure.
Our dependent variable was the percentage of correct
responses, meaning reporting what was in the
book. Our independent variables were conﬂict as a
within-subject factor (speak–no conﬂict, speak–
conﬂict) and gender (male, female) as a betweensubject
factor. Majority children displayed nearly
perfect performance in all conditions (Figure 2).
Consequently, there were no signiﬁcant differences
between conditions or genders, ensuring that boys
and girls were equally able to do the task and our
stimuli were equal in difﬁculty across point and
speak trials and both levels of conﬂict.
Results
Analyzing the minority children, the pointing trials
served as an ability check. Performance was
close to perfect on these trials, showing that the
minority children, just like the majority children
could easily identify the correct animal when tested
individually, at the beginning as well as at the end
of the session (point before: M = 0.97, SE = 0.013;
point after: M = 0.97, SE = 0.008), t(23) = 0.253,
p > .5. All reported p values in this manuscript are
two-tailed. Alpha was set at .05, and thus all results
reported as signiﬁcant are p < .05. All effect sizes
are calculated using the G*Power software (Faul,
Erdfelder, Lang, & Buchner, 2007).
Most importantly, minority children performed
signiﬁcantly better in the speak–no conﬂict than in
the speak–conﬂict condition (speak–no conﬂict:
M = 0.97, SE = 0.013; speak–conﬂict: M = 0.61,
SE = 0.072), main effect: F(1, 22) = 30.30, f = 1.18,
demonstrating conformity to peers’ opinion (Figure
2). This effect was signiﬁcantly stronger in girls
than in boys, interaction: F(1, 22) = 6.86, f = 0.56.
Furthermore, children were signiﬁcantly slower to
respond in speak–conﬂict than in speak–no conﬂict
trials (conﬂict: M = 889 ms, SE = 122; no conﬂict:
M = 617 ms, SE = 119), main effect: t(23) = 3.16,
Cohen’s d = 1.3.
Looking only at children’s responses in the
speak–conﬂict condition, minority children on average
gave a correct account of the picture in front of
them 52.8% of the time (SE = 7.04). On 37.5% of trials
(SE = 7.45), they responded conform to the
majority opinion, and on 2.4% of trials (SE = 0.94)
they reported neither what was printed on the
page nor the majority opinion. Of 24 children, 18
conformed at least once, out of which 10 conformed
more often than not. During debrieﬁng, children
were asked if they had noticed their book was different.
Of the 24 sessions, 22 included clear video
footage of who responded to the question. Of those
22 minority children, only 5 stated to have realized
their book to be different during debrieﬁng. Of
those 5 children, 4 conformed at least once, out of
which only one conformed more often than not.
Although the low numbers do not allow for a
statistical comparison between children who
reported noticing their book to be different and
those who did not, the former seem to conform
less. Children’s level of conformity signiﬁcantly
Figure 2. Mean percent correct (±SE) for all four conditions of
Experiment 1 for majority and minority children.
1762 Haun and Tomasello
decreased across trials (Pearson’s correlation of
mean levels of conformity across trials r = ).764,
N = 12). Similar effects to this were also reported
by Corriveau and Harris (2010). This might, for
example, be due to a growing mistrust toward the
majority (Corriveau & Harris, 2010) or the lack of
negative consequences to autonomous responses on
earlier trials. Boys and girls gave equal amounts of
incorrect responses (boys: M = 2.08%, SE = 1.09;
girls: M = 2.78%, SE = 1.57), but they differed to
some extent in the correct (boys: M = 68.06%,
SE = 9.56; girls: M = 37.5%, SE = 9.91) and conform
responses (boys: M = 23.61%, SE = 8.06; girls:
M = 51.39%, SE = 10.35). While boys gave more
correct responses than girls, girls gave more conform
responses than boys.
Discussion
Four-year-old children performed extremely well
in the relative size judgment task as indicated by the
high performance in the point before and point after
conditions. Hence, we assume that our participants
clearly perceived the nature of the stimuli in front of
them. In consequence, the exclusive drop in performance
only in the minority children, only when they
had to give a public response facing a unanimous
opposition (speak–conﬂict condition), indicates a
reaction to peer pressure. Children were also slower
to respond on speak–conﬂict relative to speak–no
conﬂict trials, potentially indicating effects of peer
pressure. Our data show that in these conﬂict situations,
children do not indiscriminately abandon and
replace their private perception of reality but adapt
their responses to match the majority opinion. Overall,
our participants, just like it is usually found in
adults (Asch, 1956), accurately report reality more
often than not. It is fair to say that reality holds a
greater inﬂuence on individual’s responses than
peer pressure. However, further analysis of our data
showed that in this experiment this was not true for
both genders equally. While true for boys, girls in
fact conformed more often than they accurately
described reality in speak–conﬂict trials. In comparison
to boys, girls conformed more than twice as
often. This gender difference, though more pronounced
in this sample, has regularly been reported
in adults (Bond & Smith, 1996).
Experiment 1 demonstrated strong conformity
(conformity against the child’s own judgment) to
peer pressure in preschool children. However, the
motivation behind children’s conformity remains
unclear. Adults conform following two different
motivations (Deutsch & Gerard, 1955): behavioral
optimization (informational conformity) and social
approval (social conformity). Informational conformity
describes the motivation to adopt a majority
position because it is taken to be a trustworthy
source of information about a shared objective reality.
Social conformity describes the motivation to
adopt a majority position because of the social beneﬁts.
Conforming to the majority not only minimizes
social conﬂict but also actively heightens the
group’s perception of the individual. Accepting the
fact that informational and social motivations are
often interrelated (Cialdini & Goldstein, 2004),
Experiment 2 attempted to further distinguish
between children’s motivations to conform: They
were asked to make their response in public or privately
after having been exposed to the majority
opinion. While an informational motivation would
affect both situations equally, social motivations
would only matter if the individual’s responses
were public.
Experiment 2
Our aim was to create an experimental situation as
comparable as possible to Experiment 1 but that
could additionally distinguish between informational
and social conformist behavior. After being
exposed to the majority opinion, children had
to give either public or private responses, either
when in agreement or when in conﬂict with the
majority.
Method
Participants. A total of 72 four-year-old children
(mean age = 53.64 months, SD = 1.85 months,
range = 48–56 months) participated in this study.
Children were tested in 18 gender-mixed groups
of 4 children each. Similar to Experiment 1, every
group consisted of 3 children forming a unanimous
majority and 1 child in the minority position.
Among the 18 minority children, there were
an equal number of boys and girls. Where possible,
the groups were gender balanced (11⁄18).
In all other groups, the child in the gender
minority was never the minority child. All children
were recruited from local kindergartens,
were native German speakers of normal ability
range, and came from mixed socioeconomic backgrounds.
A total of seven groups were excluded,
due to either more than nonunanimous majority
responses (four excluded) or experimenter error
(three excluded). Children were free to choose
Peer Pressure in Preschool Children 1763
not to participate at all times (0 quit). Again, the
samples reported above are the ﬁnal numbers
after exclusions.
Materials. We used the same stimuli as in Experiment
1 to create new picture books. Again, in each
session, three of the picture books were identical
(majority books), whereas one book was identical
in the order of animals across pages, but deviated
on some trials as to which size was printed on the
right-hand side (minority books). The physical
setup was also identical to Experiment 1 (see Figure
1A). Color distribution across social status positions
was again counterbalanced across subjects.
Sessions were recorded by two dv-camcorders (one
for two neighboring children).
Procedure. Instruction: In addition to the instructions
speciﬁed in Experiment 1, children were told
that their lamp would indicate if they were supposed
to say their response out loud or to silently
point to the correct animal (switched off = point;
switched on = speak). Again, children were probed
individually to ensure understanding.
Next, E assigned one of the children to be the
target child using the same procedure as in Experiment
1.
Point Trials: The child was asked to silently point
to the animal in the family picture corresponding
in size to the single individual on the opposite
page. The target child always responded last.
Speak Trials: The child was asked to say out
loud the family member, which had moved to the
opposite page.
Participants completed a total of 30 trials. On
any given trial one of the four children might have
to point. Each of the three majority children completed
two pointing trials each, one in which all
books were alike and one in which the minority
child’s book differed from the others. On these six
trials the target child was always asked to speak.
The six majority-point trials were introduced in
order to not make the minority child feel excluded
by being the only one who is asked to point. The
remaining 24 trials the minority’s responses were
counterbalanced in a 2 (design response: point ⁄
speak) · 2 (conﬂict: books alike⁄books different).
From the minority’s perspective this split resulted
in 6 point ⁄no conﬂict, 6 point ⁄conﬂict, 6 speak⁄no
conﬂict, and 6 speak ⁄conﬂict trials. Trial order was
randomized with the restriction that the ﬁrst three
trials had to be no conﬂict trials and one of the
majority children was ﬁrst of the group to point.
Target children did not behave signiﬁcantly different
in trials in which one member of the majority
pointed silently, and hence only two majority opinions
were audible and trials in which in all majority
judgments could be heard. As a result, we collapsed
them in our analysis.
Debrieﬁng: Finally children were debriefed as in
Experiment 1.
Data scoring and analysis. We videotaped all trials.
We scored the responses (pointing and speaking)
from videotapes and⁄or in situ notes. We
conducted two separate mixed 2 · 2 · 2 analyses of
variance (ANOVAs) for majority and minority children,
respectively. Our dependent variable was the
percent of correct responses, meaning reporting
what was in the book. Our independent variables
were response (point, speak) and conﬂict (conﬂict,
no conﬂict) as within-subject factors and gender
(male, female) as a between-subject factor. Majority
children displayed nearly perfect performance in
all conditions (Figure 3). The ANOVA revealed no
signiﬁcant effects between conditions or genders in
the majority children, ensuring that boys and girls
were equally capable to do the task and our stimuli
were equal in difﬁculty across conditions.
Results
Minority children were differently sensitive to a
conﬂict with majority opinion depending whether
their response was either private or public, signiﬁcant
interaction: F(1, 17) = 6.39, f = 0.61. Children
only behaved signiﬁcantly different in pointing relative
to the speaking trials when there was a conﬂict
with the majority opinion, t(17) = 3.16, Cohen’s
d = 1.5). In conﬂict trials minority children
Figure 3. Mean percent correct (±SE) for all four conditions of
Experiment 2 for majority and minority children.
1764 Haun and Tomasello
performed signiﬁcantly better when giving private
compared to public responses (Figure 3). Similar to
Study 1, children were signiﬁcantly slower to respond
in speak–conﬂict than in speak–no conﬂict trials
(conﬂict: M = 1270 ms, SE = 131; no conﬂict: M = 777
ms, SE = 209). t(17) = 2.43, Cohen’s d = 1.2.
Only looking at children’s responses in the
speak–conﬂict condition, minority children on average
gave a correct account of the picture in front
of them 64.8% of the time (SE = 8.53). On 31.5% of
trials (SE = 8.15) they responded conform to the
majority opinion, and on 3.7% of trials (SE = 1.56)
they reported neither what was printed on the page
nor the majority opinion. Of 18 children, 12 conformed
at least once, out of whom 5 conformed
more often than not. During debrieﬁng, children
were asked if they had noticed their book was different.
Of the 18 sessions, 13 included clear video
footage of who responded to the question. Of those
13 minority children only 4 stated to have realized
their book to be different during debrieﬁng. Of
those 4 children, 3 conformed at least once, out of
which one conformed more often than not. Like in
Experiment 1, the level of conformity signiﬁcantly
decreased across speaking trials (Pearson’s r = ).61,
N = 28).
Responding by pointing minority children on
average gave a correct account of the picture in
front of them 86.1% of the time (SE = 4.1). On 9.3%
of trials (SE = 2.77) they responded conform to the
majority opinion, and on 4.6% of trials (SE = 1.81)
they reported neither what was printed on the page
nor the majority opinion. Of 18 children, only 8
conformed at least once, none of which conformed
more often than not. The level of conformity stayed
constant across pointing trials (Pearson’s r = ).17,
df = 106). In comparison, pointing and speaking
resulted in equal amounts of incorrect responses,
t(17) = 0.46, but signiﬁcantly different amounts of
correct responses, t(17) = 2.9, Cohen’s d = 1.4, and
conform responses, t(17) = )3.1, p < .05, Cohen’s
d = 1.5. Children conformed more when publicly
responding than when privately responding.
Discussion
In Experiment 1 we showed that facing a unanimous
majority, preschoolers often conformed
despite knowing better. It remained unclear, however,
if the motivation behind this behavior was to
perform better, or social beneﬁts.
Experiment 2 replicated Experiment 1 showing
that children conform in conﬂict trials, despite performing
at an almost perfect level individually.
Crucially, Experiment 2 showed that, given identical
levels of conﬂict and exposure to peer opinion,
children conform much more if their response is
public (speak) than when it is private (point). They
adapt their level of conformity to the privacy of
their response ﬂexibly from trial to trial. Surprisingly,
Experiment 2 could not replicate the difference
seen between boys and girls in Experiment 1.
We have no satisfactory explanation for this.
General Discussion
The current studies demonstrate that children as
young as 4 years of age are subject to peer pressure,
indicating sensitivity to peers as a primary social
reference group already during the preschool years.
They often conform to a unanimous majority of
three peers in spite better knowledge (strong conformity)
out of social motivations mainly. Preschoolers’
levels of conformity closely match those
reported for adults (Asch, 1956). While they
respond truthfully on the majority of trials, they
conform to their peers in just over one third of
trials in both experiments. Most strikingly, they
adjust their level of conformity from trial to trial
depending on the privacy of their response. This
behavior is subject to different interpretations. On
the liberal end, one could argue that children conform
to manage the others’ evaluations of their
public self. This kind of behavior, however, has
been argued not to be strategically used (AloiseYoung,
1993) or even understood (Banerjee, 2002)
by children before around 8 years of age. To be
slightly more cautious, one might argue that children
realize the potential conﬂict that might arise
from standing alone against a majority based on
past experience. They might also remember from
past experience that the best way to avoid such
conﬂicts is by saying what everybody is saying. In
the future, even more diagnostic experiments will
have to dissect the exact mechanisms behind early
conformist behavior. In addition, in adults different
characteristics of the situation, such as size of the
majority, the relation of the participant to the members
of the majority and difﬁculty of the task have
been shown to affect conformist tendencies. Similar
consequences in children would support our
hypothesis that the early strong social conformity
we report here is adult-like in structure. How early
it emerges in ontogeny remains another important
question for future experimentation. The distinction
between conformist behavior and the underlying
motivation, as for the ﬁrst time operationalized
Peer Pressure in Preschool Children 1765
with young children in the present study, will be of
utmost importance when investigating even younger
ages. It might well be that children show conformist
behavior following different motivations at
different ages during development.
Conformity serves a crucially important function
in the transmission of human culture by promoting
quick and stable in-group uniformity, stabilizing
between-group diversity (Boyd & Richerson, 2009;
Henrich & Boyd, 1998; Henrich & Henrich, 2007;
Richerson & Boyd, 2005). No other animal exhibits
anywhere close to the kind of variability across
populations as the human species. Even the other
great apes, arguably some of the most cognitively
ﬂexible nonhuman animals, display only a relatively
small number of stable behavioral differences
across groups (van Schaik et al., 2003; Whiten et al.,
1999). This fact becomes even more striking when
one considers that humans vary much less genetically
from each other than any other great ape species
(Kaessmann, Wiebe, Weiss, & Pa¨a¨bo, 2001).
While variation in ecology (Nettle, 2009) and even
to some extent genetic variation (Dediu & Ladd,
2007) account for some behavioral diversity across
human groups, we propose that the difference in
cross-group diversity between humans and other
species is largely caused by a set of derived characteristics,
perfectly setting up human children to
adapt ﬂexibly to social⁄cultural settings. These
might, for example, include (a) a prolonged cranial
ontogeny ensuring maximal cortical plasticity while
individuals are already exposed to their social environment
(Hublin, 2005), (b) an early advance of
social-cognitive skills allowing superior access to
social information through engagement (Herrmann,
Call, Herna´ndez-Lloreda, Hare, & Tomasello, 2007;
Tomasello, Carpenter, Call, Behne, & Moll, 2005),
and (c) be-like-you social learning in which the
motivation to afﬁliate produces highly meansoriented
imitative behavior (Call, Carpenter, &
Tomasello, 2005; Horner & Whiten, 2005; Nielsen,
2009; Over & Carpenter, in press). We suspect
strong social conformity to be another addition to
this list since as of yet there are no convincing demonstrations
of strong conformity in other great ape
species (for an alternative view, see Bonnie, Horner,
Whiten, & De Waal, 2007; Hopper, Schapiro, Lambeth,
& Brosnan, 2011; Whiten, Horner, & de Waal,
2005).
In summary, the behavior documented here
shows that children as young as 4 years of age
are not only subject to adults’ inﬂuence—which
could easily arise from respect and fear of
punishment—but also subject to social pressure
from young peers. Sensitivity to peer pressure is
a sign that even at this early age children are
beginning to show the kind of conformist tendencies
that are part of the foundation of human
cultural diversity.
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