Comparison of Typically and Atypically Developing
Infants’ False Belief Understanding



of Mind (ToM) is understanding others people’s mind (Peterson,
Wellman, & Slaughter, 2012). This is called as theory, because it
is predicting other people’s attributions and it is not directly observable (Premack
& Woodruff, 1978) . This ability is
very crucial for human beings to be able to understand each other and to be
able to predict each others’ behaviour; because of that, theory of mind (ToM)
have excited the attention of researchers for years (Yott
& Poulin-Dubois, 2016). Theory of mind
comprises of different parts, however the testing of false belief understanding
is accepted as the litmus test for it (Poulin-Dubois
& Yott, 2017).

concept theory of mind, false belief can be assessed as people do things in the
direction of what they consider, even if they are not true (Slaughter,
2015). In
traditional testing of this task, children get a story where the person in the
story misses information, but children know. So the person in the story has
false belief. After that, children are asked about the belief of person in the
story with questions such as: what the person thinks or where this person will
look for an object to get explicit response (Grosse
Wiesmann, Friederici, Singer, & Steinbeis, 2017).  A lot of studies, which are done only this
task, showed that children can pass that task after 4 years old; however before
four years old, they have difficulties to pass that task and they fail (Gopnik
& Slaughter, 1991; Pellicano & Rhodes, 2003). However, newly
done studies showed that there is an important developmental change from age of
3 to 4; while 3 years old children fail at explicit false belief task, they can
pass implicit false belief task (Grosse
Wiesmann et al., 2017).

of Mind (ToM) concept is very important that has studied for years. However; findings
of many studies arouse theory of mind researchers’ curiosity and lead them to
focus on mostly theory of mind development in infancy (Heyes,
2014; Slaughter, 2015).  In this proposal, development of understanding
of others’ mind in infancy and; comparisons of typically developing infants and
atypically developing infants in terms of false belief understanding is taken
into consideration.

Literature Review

            Theory of mind in

these new research findings, many studies have focused on very early occurrence
of theory of mind in infancy. Poulin-Dubois and Yott (2017) stated in their
paper that the traditional knowledge about development of theory of mind after
age 4 was shaken with Clements and Perner’s research in 1994. They found that
eye movements of 2 years 11 months old children and older children indicated
that they can understand the false belief. With these results, a lot of
researchers began to focus on theory of mind concept from age 2 to infancy.

False task
understanding of theory of mind in typically developing infants

Clement and Perner’s (1994) results, studies began to take into consideration
theory of mind testing in infancy term. Different mental states of theory of
mind was taken into consideration by researchers like early reasoning about
desires among 14 and 18 month old infant (Repacholi
& Gopnik, 1997); imitation of
intentional actions among 14 and 18 month (Olineck
& Poulin-Dubois, 2007); psychological
reasoning  in 18-month-old infant (Song,
Onishi, Baillargeon, & Fisher, 2008). These studies
showed that even though infants could not explain verbally, they were showing
different attitudes during testing of different mental states. In addition to
these studies, because false task understanding is seen as litmus test of
theory of mind (Poulin-Dubois
& Yott, 2017), to examine
false belief  from infants’ perspective
will be more helpful to understand this developmental process. In this research
proposal, false belief understanding of infants is studied.

of all, because infants cannot talk, researchers examined the infants looking
behaviour thorough using some paradigms which helps to understand their false
belief understanding.  In 2005 Onishi and
Baillargeon developed a novel nonverbal task to examine15-month-old infants’
ability. In their task, they wanted infants to guess an actors’ behaviour on
the true or false belief about a toy’s hiding place. Findings of that study
showed that infants use mental state to predict others’ behaviour.  Surian, Caldi and Sperber (2007) assessed
infants looking by showing them animations and they stated the view that
infants have an incipient meta representational ability, which provides them to
attribute beliefs to agents. He et al. (2011) used violation of expectation change-of-location
and unexpected- content tasks to see false belief understanding in 2,5-years-old.
They also supported the false belief understanding in toddlers.

some studies demonstrated that infants understand false belief, there are still
some doubts about it (Slaughter,
2015). In
the studies, different age groups and different ways were used to clarify this
issue. For instance, Kovacs,Teglas and Endress (2017) took 7-month-old infants
(which are younger than other studies) as participants to their studies. They
also found that 7-month-old age infant took into consideration of other
people’s belief.  Yott and Poulin-Dubois
(2012) used behavioural rules for 18 month-old-infants; Buttelmann, Carpenter
and Tomasello (2009 )used helping behaviour paradigm for 18-month-old
infants;Southgate et. al (2010) examined infants’ tracking the status of a
communicator’s epistemic state; Scoot, Baillargeon, Song and Leslie (2010) showed
a search paradigm to 18-month old infants. In 2007, Southgate, Senju and Csibra
measured infants’ looking behviour by using eye tracker. They examined action
anticipation of 2 year-old infants. In all these studies, even situations and
methods are different, infants faced up a false belief testing. Findings of all
studies showed that infants look differently or attribute differently, when actor
when the actor attributed by basing on a false belief.

a result, after the awareness of children can understand false belief task
before age 4, many research were done on the development of false belief
understanding of typically developing infants. Actually, the studies that are
mentioned above include typically developing children as participants. In these
studies, different paradigms and different methods were used while testing
false belief understanding in infancy term. Studies’ results investigated that infants
understand false belief of agents.



            False task
understanding of theory of mind in atypically developing infants

that were mentioned above were done to assess false belief understanding of
typically developing infants. When the literature was reviewed, it was seen
that even there are studies on false belief task of atypically developing children
Surian & Leslie, 1999); according to
our knowledge, there is not any study that specifically focus on false belief
understanding of atypically developing infants (Kampis,
Fogd, & Kovács, 2017).

the literature is reviewed, it was observed that in 1999 Surian and Leslie
compared the competence and performance of autistics and normal 3-year-old
children in terms of competence and performance in false belief understanding. They
used a standard prediction of action task (Sally/Anne story). In this study,
normally developing 3 years old children were able to understand the
protagonist’s false belief. Autistics children attended the 3,5-year-old level performance
in this study and they failed standard prediction task. Even this study included
3 and 3,5 years old children, it compared the false belief understanding among
typically and atypically developing children. In another study also theory of
mind abilities of young siblings of children were studied. Participants were 4
years old. They were divided as siblings of children with autism and siblings
of typically developing children. There was not any significant difference
between groups; however, differences were found within group results between
Tom ability and receptive language.  

the studies were reviewed, according to our knowledge, it could not be found any
study about false belief understanding among atypically developing infants.
However, a study was found which compares typically developing infants and
atypically developing infants in terms of gaze following, not false belief
understanding (Thorup,
Nyström, Gredebäck, Bölte, & Falck-Ytter, 2016).  They used eye tracking to assess gaze
following. They found that infants at familial risk for ASD followed gaze less
likely when adult’s eyes were giving directional information than when both
eyes and head of the adult were giving information. Actually, that study gave
knowledge about there is a statistically significant different looking behaviour
between typically and atypically developing infants.

a result, there is no study specifically focuses on comparisons of typically
and atypically developing infants in terms of false belief understanding. Studies
that were done among 3 or 4 years found differences between groups and some of
them found in within group differences. An also one study that was done with
infants showed that gaze following of the infants was different for both




            Comparisons of
typically and atypically developing infants’ false belief understanding

of mind (ToM) shows people’s social cognition (Poulin-Dubois
& Yott, 2017).  Problems in theory of mind can be symptom of
atypically development, which is known as a core deficit of autism (Shaked,
Gamliel, & Yirmiya, 2006).  Early prediction of this deficit make easier
to early intervention. Some studies discovered that implicit false belief
understanding of that theory can be gained from before age 3 to 7 month old (Buttelmann,
Carpenter, & Tomasello, 2009; Clements & Perner, 1994; He, Bolz, &
Baillargeon, 2011; Kristine, 2005; Melinda, Téglás, & Endress, 2017; Sarret
& Rommelfanger, 2015; Victoria Southgate, Chevallier, & Csibra, 2010; Surian
& Leslie, 1999; Yott & Poulin-Dubois, 2012, 2016).  However, if it is any deficit in gaining that
ability in infancy can give information about later development.

a lot of studies demonstrated that infant could understand false belief of others;
there is still hot debate about whether these findings showing the reality of
infants’ understanding of others’ mind (Poulin-Dubois
& Yott, 2017; Slaughter, 2015).  Assessment of infants’ false belief
understanding bases on limited, nonverbal facts and these restricted facts cause
these debates (De
Bruin & Newen, 2012; Grosse Wiesmann et al., 2017; Scott, Richman, &
Baillargeon, 2015).  Implicit understanding

occurs in the brain of infants, it
is really based on restricted facts. However one of the best ways to clarify
these doubts will compare typically and atypically developing infants in terms
of false belief understanding, which has never done before.  As mentioned above, deficits in understanding
others is core symptom of autism and it gives information about social
cognition of people. Comparisons of typically and atypically developing
infants’ false belief understanding help to get more knowledge about
understanding of others in infancy.  In
the lights of all these findings and literature, the purpose of this research
is compare false belief understanding of typically and atypically developing
infants to get more information about their social cognition.



of the study will be a total of one hundred 9-month-old infants. Fifty infants
will be high-risk infants (HR group) who have at least one older sibling with an
autism spectrum disorder (ASD). Other fifty infants will be infants who have
low-risk. Low-risk infants (LR group) are infants who do not have any person
with ASD in their family history or at least one typically developing older

will be taken from Child Development Unit of University of Kent in Canterbury,
England. 6-9 and 12-month-old both typically and atypically developing infants
come to that unit for infant testing. These infants can be included to this

the study is applied to infants, parents will be informed about study and all
ethical issues related with study’s process and confidentiality. A consent form
will be taken from parents. After permission is taken by parents, infants will
be included.

             To recruit more infants announcements will be
presented in study’s website and university’s website. In addition to that,
schools, special working places related with autism spectrum disorder and clinical
centres will be contacted to reach these parents. Participants’ older sibling
with ASD has to be diagnosed as formally by a trained person. Diagnostic
criteria must be based on American Psychiatric Association (2000) and World
Health Organization (1992).

information form will be given to parents. In this form, information about socioeconomic
level of the family (by looking at family income), education level of parents,
developmental history of the infants will be taken. The questions related with
developmental history of infants will be about whether they have any
developmental disorder, whether they have any impairments and whether they get
any medical interventions. With this information, infants who have same
characteristics will be included in this study.


materials that were used by Yott and Poulin-Dubois (2016) will be used in this
study. They used a stage-like apparatus (107 cm x 61 cm x 211 cm). There is a
window (86 cm x 91 cm) in which the experimenter comes up. There is a flat
surface on the window. On the top of the surface there is a small place for a
digital camera to record looking behaviour of infants. The infants will observe
experimenter approximately from 110 cm from display. Infants can observe on a
high chair or on their parent’s lap. During the experiments, all parents are
requested to be silent. There is a white curtain to cover the window. It will
be used by the experimenter, while experimenter is testing true and false tasks.
Infants’ looking behaviours are coded by two observers while testing

Belief tasks

and Poulin-Dubois (2016) presented both a red cup or yellow duck for belief
task. In this study, the read cup will be used. The red cup (7.5 in diameter,
10.5 cm high), a yellow box and a green box (14 cm x 14 cm x 14 cm) are
materials of that task. There is an opening side of the each box on the cup
side. It was covered with a fabric fringe. Each box has a rectangular opening
underneath. That opening place lets the experimenter to use to change place of
the cup from one box to another. This is done thorough a magnet that is put
under the cup and under the stage.

and Procedure

room of the Child Development Unit of University of Kent will be designed
according to belief task. When parents and infants come to unit, firstly
parents will fill consent form and information document. After that, belief
task will be applied to infants.

Measures of false
belief understanding

this study, to measure false belief understanding, Yott and Poulin-Dubois’
(2016) belief tasks will be used. They adapted the belief tasks from Onishi and
Baillargeon’s (2005) study. In this adaptation they measured both true and
false tasks non-verbally. These tasks are based on violation of expectation
paradigm. Belief tasks include three familiarization trials, and these trials
are followed by a false-belief induction trial and false-belief test trial and
then true-belief induction trial followed by a true-belief test trial.

familiarization testing, the experimenter takes the cup (which is between
boxes) and puts it one of the box and stays like this for a while. If the
infant looks away 10 seconds or looks the trial 2 seconds and looks away 10
seconds trial finishes. It is repeated second and third time.

false belief task, the cup is moved to another box and experimenter does not
have any idea about this changing; however experimenter opens the box with cup.
In true-belief task, the cup is left in first box (which both infants and experimenter
observe) and the experimenter opens that box (because the experimenter sees cup
in this box before).

Coding and

times of infants in each trial will be coded by two observers. If infants do
not observe the still phase, they are not taken to analysis. To measure
interrater reliability, Pearson product-moment correlations will be found and

Key Predictions

this study, it is expected that there is a statistically significant difference
between typically developing infants and atypically developing infants when
they are compared in terms of their false belief understanding. According to
theory of mind, human begins have social cognition and they understand other
peoples’ mind and state, if they are developing typically. However, if there
are deficits in theory of mind, that can be because of atypical development.
Because of that, statistically significant difference between typically
developing infants and atypically developing infants can be expected like
typically developing infants have more false belief understanding than
atypically developing infants.

Data Analysis and Power Calculations

analysis of data will be done by using Statistical Package for the Social
Sciences Software (SPSS). Group mean differences of typically and atypically
developing infants will be analysed by using independent t-test.