Motivation and emotion/Book/2015/Autism and emotional development

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Autism and emotional development:
How does autism affect children's emotional development?
Go to a 3 min. audiovisual overview of this chapter.

Overview

There has been a lot of research that emphasises and highlights the significance of a child’s physical growth and development but not as much research focusing on a child’s emotional growth and development. So how does a child grow to understand who they are and what their sentiments are? How do they develop the ability to communicate and form friendships with others? (Reinsburg. K., 2009; Brooks. A, n.d.) These questions need to be addressed as they are the basis for the development of a child’s socio-emotional well-being from age zero to age six: their self-confidence, sense of self value and esteem, their compassion and their ability to develop meaningful relationships. Unfortunately as Brooks (n.d.) highlights, more often that not, people notice the absence of a child’s social and emotional proficiencies rather than their accomplishments and this has imposed limitations on this area of study. This chapter specifically focuses on the struggles of children with an autism spectrum disorder particularly in relation to their ability to recognise and show emotions, to interact with others through verbal and nonverbal communication and their elasticity in thought and action through their response and perception in their social interactions (American Psychiatric Association, 1994; Begeer, 2005).

Figure 1. Autism Awareness Ribbon

What is Autism?

Autism and Autism Spectrum Disorders are apart of a series of multifaceted disorders that can affect a child’s brain development. Under the DSM-V manual it has been acknowledged as a separate pervasive disorder from that of intellectual disability, and all autistic disorders have been combined under one diagnosis of ASD. At one time autism was thought to be a rare disorder but autism is a disorder that has been around for centuries and for decades an extensively studied topic.  However, as awareness has grown so has its prevalence. Research has shown that Autism is more prevalent in females who have an IQ under 35 and males who have a higher (Durand & barlow, 2013).  It is not known why this is the case. In earlier times before autism was recognized  as a disorder, austism was attributed to  bad parenting, a diagnosis which obviously had a devastating effect on parents wellbeing (Bettelheim, 1976). A lot parents were left feeling guilty and responsible for their child’s condition, being describes as cold and perfectionists (Kanner, 1949).

Autism, has an array of symptoms, all of which affect a child’s ability to interact on a social level, and their verbal and nonverbal communication. Statistically one third of autistic children never acquire speech (Tager-Flusberg, 2009). Even with a small amount speech it is abnormal and often very repetitive (Durand & barlow, 2013).

Furthermore, autism can affect intellectual capabilities, coordination and attention levels and physical health, with restricted patterns of behaviour, interests and activities (Durand, 2011). Children with autism struggle to express themselves emotionally and to understand situations involving themselves and others.  These aspects of the disorder have a negative impact on the child’s development because children need those abilities  and underdevelopment in emotional expression has a negative affect on the child’s social interactions and communication (Kasari & Sigman, 1996).  Indeed, the severe impairment in social interaction makes it significantly difficult for children with autism to interact socially with other individuals.  These children are “cut off” from the world around them (Taylor, 2005).

Figure 2. Autistic child's repetitive routine of stacking cans

There is however at one end of the Autism spectrum a milder form of autism known as Asperger’s Disorder. In contrast to more severe forms of autism, Asperger’s is characterised only by a significant impairment in social interaction and the development of restricted repetitive stereotyped patterns of behaviour, interests and activities (American Psychiatric Association, 2000). Compared to other forms of autism, there are no significant delays in language or emotional acquisition in Asperger's Disorder (American Psychiatric Association, 2000). Children with Asperger’s are normally quite verbal, and hold unusual and limited, but factual, interests (Volkmar et al, 2009).

This video highlights example of children with varying degrees of Autism Spectrum Disorder and the efforts made to aid in their emotional development at school. What is autism?

Autism and the media:
Awareness and acceptance of Autism is increasing as its prevalence increases. And recently in the media major changes have been announced to the Children's TV program Sesame Street - it's first Autistic female characters is being introducing. The TV show is introducing this character to encourage acceptance of differences in children's peer groups. The aim of this is to help reduce bullying as Autistic are five time more likely to fall victim to bullying than other children. It is the first time that Autism will be portrayed on a TV program.

Emotional Development

What is Emotional Development?

A person’s emotional development is based on social experience and sense of self- dating back to their childhood (Reinsburg. K., 2009; Brooks. A, n.d.). Emotional development teaches children specific reactions to emotional situations helping them to understand and control their emotions.  During this period of a person’s life, from age zero to six years of age, the nurturing of development is key to aiding the growth of relationships specifically with direct family members through repeated interactions and also to the development of the child’s brain structures.

Typical Emotional Development - Theoretical Approaches

Emotional development or early child hood mental health has a knock on effect to the development and stability of other functions in a child’s body specifically cognitive, motor and even language development (Reinsburg. K., 2009). These are connected through how a child comprehends what they are feeling and how they express these feelings outwardly along with their ideas. These developments require a balance - a balance between internal control and understanding of emotions and external interaction and communication.

According to PBSparents (n.d.) from age one a child has the ability to:

From age two:

From age three:

From age four:

From age five:

It is said that the healthy social and emotional development of a child, such as the defined time frame above, means the child will develop relations, persistence and the ability to focus their attention and regulate their behaviour to discover and learn. Children of typical emotional development, like above, tend to express ideas and emotions and display compassions and empathy towards others. The ability to control emotions in highly emotional and intense situations is also indicative of stable emotional development.

Theoretical approaches to defining a stable emotional development attempts to explain and outline what kind of environment is best suited for the child’s emotional development. There are two key approaches that when studied together demonstrate how a typical emotional development in an environment with strong attachments would occur in a child. These are the Psychoanalytic Approach from Erikson and the Attachment theories from Bowlby. Together they show how a “typical” child would grow and develop emotionally according to defined standards. However it must be noted that the perception of any atypical type of development is based on what society has historically has defined as a typical set of emotions reciprocated by an inbuilt reaction that promotes their wellbeing (Schaffer, 2005).

Erikson’s Model (Brooks, n.d.; Mcleod, 2013)

Stage     Description
Hope

0-2years

Learning Basic Trust Versus Basic Mistrust:

The nurturing of a child leads to the development of trust and optimism however insecurity results in the absence of a nurturing environment.

Will

18mths-4years

Learning Autonomy Versus Shame:

“The Psychosocial crisis” leads to self-assurance and control. This is from the confrontation of tantrums and stubbornness.  

An example of this emotional confrontation is the “terrible two’s” stage in a toddlers life. 

Purpose

3-6years

Learning Initiative Versus Guilt:

The “play age” of imagination, sharing and cooperation with others as well as leading and/or following.

It is clear that during this stage differences in children’s emotional development, specifically in their interactions with others, would first start to be observed.

Competence

From 5.5 years

Industry vs Inferiority:

This stage introduces rules and structure to the social interaction sphere and a new form of learning. It is the behaviour of trust and initiative that is industrious and the shame and guilt that is inferiority.

Attachment Theories

Attachment in this chapter concerns the behaviour of a child towards the main caregivers and how this attachment influences and impacts their development emotionally (Bowlby, 1969). It does not have to be shared Mcleod (2013).  Bowlby’s original work in attachment demonstrates the significance of the child’s relationship with their mother especially at an early age in providing love, safety and security. His work with emotionally disturbed children highlighted the significance of this attachment under highly stressful conditions. He divided the attachment into 4 stages.

Age Types

of Attachment

Description 
0-3mths Indiscriminate  An inbuilt reaction means the child responds in kind and can form an attachment to all.
4+mths Preference  This is the stage where infants start to differentiate and have a preference between caregivers.
7+mths Single

Preference

A preference is developed and reasoned to be for comfort and protection. Emotions of fear and unhappiness with reactions like crying when they are separated from that figure.
9+mths Multiple

Attachments

This is the start of child independence and meaningful social interaction.

Atypical Development: Emotions and Children with Autism

A major aspect of autism is the restricted behaviours and emotions that make it nearly impossible for an autistic individual to hold a conversation with another person because they are either unable to or unwilling to interact. Social interaction is the shared experience and practice between peers in which people effectively initiate and respond to social stimuli (Shores, 1987; Bauminger, 2002). It is well recognized that the social participation of children with autism in peer interaction can be quiet low and poor in quality (Sigman & Ruskin, 1999). Research has shown that these difficulties in socio-emotional understanding has caught children, especially those with high functioning autism, in a “vicious circle of isolation” (Bauminger, 2002) and these children struggle in social cognitions, interactions and in expressing their own emotions (Bauminger, 2002; American Psychiatric Association, 1994; Volkmar, Carter, Grossman, & Klin, 1997). Most autistic children have preference to ritualistic behaviour or maintenance of sameness, like waving hands in front of their eyes or spinning in circles, this behaviour clearly suggests interaction with others is unpredictable for them (Durand, 2011).

As many researchers, including Stanton (2009) have pointed out, these autism caused distinctive emotional deficits, means that an autistic child is also socially impaired. Stanton (2009) highlights:

Age  Atypical development (Stanton, 2009) Typical development (PBS parents, n.d.)
Birth to Twenty-four Months An autistic child does not smile or pay attention to new faces

Shows minimal affection

Show distress in the presence of anyone

No attempt to attract attention of others

Has trouble with new objects or experiences

Does not acknowledge sounds, smiles, or facial expressions

Lacks social skills or prefers interactions only with familiar adults

Does participate in play or laugh

A child without autism starts to smile and notice new faces. A child without autism can show pleasure in the presence of a familiar figure.
Two to Three Years Autistic child does not respond to people outside the family

Continues to have great trouble separating from parents

Trial and error for emotional development – occurs through exploration and pretend play

Social interaction with other children.

Feelings are being labeled now that they recognise off facial expressions.

Three to Five Years Continues show emotional distress when separated from parents.

Refuses to respond to people and has little interest in other children

Does not engage in a variety of activities.

Does not express a range of emotions or appears unengaged much of the time

During conflict or emotional distress, the child will seek help or comfort, or provide help to others.

They have ability to interact and maintain friendships with adults and children. They like to interact in groups – learn to show sympathy and suggest resolutions to conflict.

Children show much greater independence by resoling their own conflicts and demonstrating compromise.

They learn to manage intense emotions through talking or drawing.

Social Cognition

Researchers define social cognition as the child’s capacity to decipher verbal and nonverbal social and emotional prompts – their emotional recognition, their ability to collate information in their peripheral and central eye line and their ability to initiate interaction (Bauminger, 2002; Gepner et al, 2001). 

Distinguishing expression in emotional recognition in oneself and in others aids in deciphering contextual information.  In children, it is the basic emotions of happiness, sadness, anger and fear, that are most prevalent and the simplest to decipher. Furthermore the acquired skill of comprehending more complex emotions of – embarrassment, empathy, loneliness, or surprise that takes more brain processing power. It has been found that even high functioning autistic children are much less competent than the norm when it comes to distinguishing such emotions, even the simplest of them (Hobson 1986; Dapretto et al, 2006; Gepner et al, 2001). Distinguishing emotions for autistic children means the ability to recognise simple emotion without the capability to explain the causes of the emotion. An absent quality in autistic children is the ability to decipher information in their central eye line. Autistic children tend to pay particular attention to the peripheral and physical characteristics of a situation not the social meaning (Dapretto et al, 2006).  For example when shown a picture of two people arguing, a child who does not have autism could comprehend that the figures were upset and angry, and therefore arguing. They could also determine what kind of relationship the two figures have. An autistic child does not have the ability to do this. They would see the figures in proximity to each other, articles around the figures and colors. This is demonstrated in many studies such as Klin (2000) wherein it is shown that a child with autism was not able to understand cartoon figures.

Many researchers of autism disorders place emphasise on the complex idea of the theory of mind. This theory concerns the ability to decipher a person’s mental state including for example their beliefs, desires, intentions, emotions and a person’s ability to predict behaviour and its consequences (Dapretto et al, 2006). The theory is based on studies of children five years old and younger, and it must be noted that there is limited substantial research involving children above that age group. Furthermore children with typical or normal emotional development, have at this age the ability to comprehend social situations according to emotion. Autistic children however find it difficult to differentiate between what they think is happening in a social situation and what is actually happening. This difficulty can be associated with  their focus of attention being on the social situation’s  peripheral information . The theory of mind explains deficits in the form of emotional impairments found in autistic children (Lantz, 2002). Typically it is around the age of five months that the child starts to understand facial expressions.  This nonverbal behaviour reflects their own behaviours and responses depending on the predicted consequences (Lantz, 2002). Lantz (2002) highlights the 1994 study by Dawson and Osterling of children attending a birthday party prior to being diagnosed as autistic. These children lacked attention and emotions such as surprise or happiness. Moreover children come to discover that the behaviour is goal directed (Lantz, 2002). They learn to intentionally act in certain way to bring desired consequences (Lantz, 2002; Baron-Cohen, 1993). Something as simple as wanting to held by their mother – would be directed by crying and arms stretched out. The theory of mind highlights that a struggle in this for autistic children is to focus attention, specifically, focusing on more than one thing at the one time.

Interaction and Expressing Emotions

Charles Darwin said, “[that] the movements of expression of the face…are in themselves much more of importance
for our welfare” (Cole et al, 1994). 

Human faces have the ability to communicate information about ones character and emotions through the simplest of movements. It is the first and most powerful basis of information gathering for facilitating emotional and verbal communication, and for social interactions (Gepner et al, 2001). Facial expressions are key to understanding emotions and in turn social interaction as they highlight an individual’s intentions and promote appropriate responses (Bal et al, 2010). The formation of relationships and acceptable social interactions are based on emotional understanding and recognition. This also correlates to a child’s ability adapt to social situations rather than internalising emotions and behaviour (Bal et al, 2010). Furthermore research has shown that autistic children have scanning and visual tracking difficulties when trying to comprehend facial expressions that sway the focus of their attention. This explains an aspect of child’s social detachment if they have autism because is has been shown that specific regions of a face express specific emotions (Bal et al, 2010). Bal et al (2010) and Dimberg and Petterson (2000) also note that negative emotions are more often expressed in the upper region of the face and positive emotions in the lower region -around the mouth. Thus an individual must be looking for facial clues and cues to recognize emotions and to decipher this information.  Children with autism are unable to do this.

Figure 3. Expressions

The ability to express thoughts and emotions or the ability to participate socio-emotionally is another struggle for those children with autism. Autistic children do not proactively engage in social interaction with others, like smiling and laughing (Kim et al, 2009). Bal et al (2010) and others highlight this along with showing that children with ASD are less capable of coordinating social cues, perceiving others’ moods, and anticipating others’ responses. It has also be noted and cannot be ignored that vast numbers of children with high functioning autism are aware of their inability to do this and express the desire to have such abilities (Losh et al, 2006). Losh et al (2006) highlights this is contrary to the original thoughts of many researchers and professionals (e.g. American Psychiatric Association, 1994; Kanner 1943) in regard to an autistic child’s emotional indifference and absence of facial expressions. But autistic children do have ability to express simple emotions (Losh et al, Bauminger, 2002; Depretto et al, 2006). It is only the complex emotions where children with high functioning autism have been shown to require prompts to express such complex emotions (Dapretto et al). Furthermore it takes them longer to display such emotions than the typical developing child. Dapretto et al (2006) also highlighted the strategy required for autistic children to express the view – “I think”.

Encouraging Emotional Development

Research has demonstrated that there are straightforward steps to encourage children’s emotional development. Furthermore these steps can help change the stigma surrounding autism and to allow it to be more accepted in society. These steps can be easily modified and applied to autistic children to assist their emotional development. Other research states that focusing the attention of an autistic child is key and to get a response from an autistic child exaggeration may be required (Raisingchildren.net, n.d.). Encouraging eye contact is another way to promote social interaction in autistic children. To further encourage interaction with strangers a child’s need to attend to that person will have to be pointed out for them (Raisingchildren.net, n.d.). Of course reward and positive encouragement towards their simple social achievements is advisable. This will encourage social contact and interest. Raisingchildren.net (n.d.) highlights that autistic children find interest in pictures, so displaying facial expressions, routines, even family photos in small colourful flip book, for example, can encourage familiarity of family members and friends and also emotions.

Steps to Encouraging Emotional Development:
  1. Routines - Young children learn through consistency and responsiveness whether that is through responsiveness or reward. Working out the balance is key, especially in autistic children in discovering what their own enjoyments and interests, and what sooths them.
  2. Nurturing environment - Affection and love provide an “emotional holding environment” a place where they can manage their emotions and feelings by trusting their caregiver (Reinsburg, 2009). This environment teaches children to also express emotion and care themselves.
  3. Encouraging exploration - Discovering new emotions and feelings through exploration allows children to increase their confidence and be independent. It makes it easier for children to accept change.
  4. Encourage developing skills - Newly gained skill ignites excitement and happiness in children. Showing interest to a child’s skill increases self-competence and emotional stability.
  5. Promote expression of feelings - It is hard for children to learn how express their emotion and know what causes it. Without this they cannot manage their feelings and temperaments. Labeling feelings through various media’s as examples show children this. For autistic children, it important to parent and caregivers to promote and point out such emotions in media that has picture of videos, to give them a real world representation of emotions. Furthermore being responsive to their emotions is key as well. Such as pointing out to them that are happy because they are smiling. Rasingchildren.net also points that a parents or caregivers exaggeration of the own emotions in response to something their child has achieved promotes the self-confidence the autistic child needs.
  6. Respect differences - All children are different and those who we surrounded by influence social interaction. Children learn from the people in their immediate proximity thus it is important to encourage understanding of others, including children with autism, to positively affect and change the stigma surrounding autism.
Reinsburg (2009)
Emotional Adjustment in Primary School:
Research from Raver (2003) highlights that a child’s emotional adjustment to the school environment is vital to their development into adolescents, especially for children with autism. The early stages of school can cause emotional difficulties for children with autism. These difficulties emerge even on the first day attendance at school because going to school changes their familiar routines and patterns. For autistic children this brings confusion and even frustration and emotional outbursts. Further difficulties include inability to pay attention, following directions and most importantly the interacting with other children. The ability to build relations is based off of the regulation of emotions and participation things for which an autistic child is not emotional developed.

Conclusion

External Links

Emotional Development

Parenting and Emotional Development in Children

Emotional Development in Children

References

American

Psychiatric Association (1994). Diagnostic and Statistical Manual of Mental Disorders. (4 ed.) Washington D.C.: A. P. A.

American Psychiatric Association. (1994). Diagnostic and statisti- cal manual of mental disorders (4th ed., rev.). Washington, DC: American Psychiatric Association.

Bal, E., Harden, E., Lamb, D., Van Hecke, A., Denver, J., & Porges, S. (2010). Emotion recognition in children with autism spectrum disorders: relations to eye gaze and autonomic state. Journal Of Autism & Developmental Disorders, 40(3), 358-370 13p. doi:10.1007/s10803-009-0884-3

Baron-Cohen, S. (1993). From attention-goal psychology to belief-desire psychology: the development of a theory of mind, and its dysfunction.

Bauminger, N. (2002). The facilitation of social-emotional understanding and social interaction in high-functioning children with autism: intervention outcomes. Journal Of Autism & Developmental Disorders, 32(4), 283-298 16p

Begeer, S. (2005). Social-emotional development in high-functioning children with autism Social and emotional skills and understanding of children with autism spectrum disorders. Universiteit Amsterdam: prof.dr. T. Sminia.

Bettelheim, B. (1967) The empty fortress. New York, NY: Free Press

Brooks, A. (n.d). Social and emotional development in babies and children. http://www.kidspot.com.au/discoverycentre/Development-Development-Social-and-emotional-development-in-babies-and-children+5368+553+article.htm

Cole, P. M., & Michel, M. K. (1994). THE DEVELOPMENT OF EMOTION REGULATION AND DYSREGULATION: A CLINICAL PERSPECTIVE. Monographs Of The Society For Research In Child Development, 59(2/3), 73-100. doi:10.1111/1540-5834.ep9502132765

Dapretto, M. M. (2006). Understanding emotions in others: mirror neuron dysfunction in children with autism spectrum disorders. Nature Neuroscience, 9(1), 28-30.

Dimberg, U., & Petterson, M. (2000). Facial reactions to happy and angry facial expressions: Evidence for right hemisphere domi- nance. Psychophysiology, 37, 693–696.

Durand, & Barlow. (2013). Essentials of Abnormal Psychology. Wadsworth, Cengage Learning: Hague.

Durand, V.M. (2011)Disorder of Development. In Barlow (Ed.), Oxford handbook of clinical psychology (pp551-573)

Gepner, B., Deruelle, C., & Grynfeltt, S. (2001). Motion and emotion: a novel approach to the study of face processing by young autistic children. Journal Of Autism & Developmental Disorders, 31(1), 37-45 9p.

Hobson, R. P. (1986). The autistic child’s appraisal of expressions of emotion: A further study. Journal of Child Psychology and Psychiatry, 27, 671–680.

Hooper, S. R., & Umansky, W. (2014). Social and Emotional Development in Children with Autism.

Kanner, L. (1943). Autistic disturbances of affective contact. The Nervous Child, 2, 217–250.

Kim, J., Wigram, T., & Gold, C. (2009). Emotional, motivational and interpersonal responsiveness of children with autism in improvisational music therapy. Autism, 13(4).

Kim, J., Wigram, T., & Gold, C. (2009). Emotional, motivational and interpersonal responsiveness of children with autism in improvisational music therapy. Autism, 13(4).

Klin, A. (2000). Attributing social meaning to ambiguous visual stim- uli in higher-functioning autism and Asperger syndrome: the so- cial attribution task. Journal of Child Psychology and Psychiatry, 41, 831–846.

Lantz, J. (2002). Theory of mind in autism: Development, implications, and interventions. The Reporter, 7(3), 18-25.

Losh, M., & Capps, L. (2006). Understanding of Emotional Experience in Autism: Insights From the Personal Accounts of High-Functioning Children With Autism. Developmental Psychology, 42(5).

Losh, M., & Capps, L. (2006). Understanding of Emotional Experience in Autism: Insights From the Personal Accounts of High-Functioning Children With Autism. Developmental Psychology, 42(5).

Mcleod, S. (2013). Erik Erikson. http://www.simplypsychology.org/Erik-Erikson.html Retrieved from http://www.simplypsychology.org/Erik-Erikson.html

McLeod, S. A. (2013). Erik Erikson. Retrieved from www.simplypsychology.org/Erik-Erikson.html

PBSparents. (n.d.). Child Development.   Retrieved from http://www.pbs.org/parents/child-development/

Puvanenthiran, B. (2015). Sesame Street introduces first character with autism. The Sydney Morning Herald. Retrieved from http://www.smh.com.au/entertainment/tv-and-radio/sesame-street-introduces-first-character-with-autism-20151022-gkf8ni.html

Raver, C. C. (2003). Young Children's Emotional Development and School Readiness. Society for Research in Child Development's Social Policy Report, 16(3), 3-19.

Reinsburg, K. (2009). What is Social-Emotional Development? http://www.abilitypath.org/areas-of-development/social--emotional/what-is-social-emotional.html

RasingChildren.net. (n.d.). Emotional development in children with autism spectrum disorder.  Retrieved from http://raisingchildren.net.au/articles/autism_spectrum_disorder_emotional_development.html

Shaffer, R. D. (2005). Social and personality development. Wadsworth Publications, Belmont, CA. Siegal, M. (2007). Marvelous minds: the discovery of what children know. Oxford University Press, New York, NY Slentz, K., & Krogh, S. (2001). Early childhood development and its variations. Retrieved from: http://books.google.com.au/books?id=_8Typ-IJ9LsC&printsec=frontcover&dq=Slentz+and+Krogh&hl=en&ei=OpLWTLTDFoexcYeZ0dQL&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCcQ6AEwAA#v=onepage&q&f=false

Shores, R. L. (1987). Overview of research on social interaction: a historical and personal perspective. Behavioral Disorders, 12, 233–241.

Sigman, M., & Ruskin, E. (1999). Continuity and change in the social competence of children with autism, Downs syndrome, and de- velopmental delays. Monographs of the Society for Research in Child Development, 64 (1, Serial No. 256).

Stanton, K. (2009). Signs of Possible Developmental Delays: Social and Emotional Development

Volkmar, F. R., Carter, A., Grossman, J., & Klin, A. (1997). Social development in autism. In D. J. Cohen, & F. R. Volkmar (Eds.), Handbook of autism and developmental disorders (pp. 173–194). New York: Wiley.

Volkmar, kiln, Schultz & State (2009). Pervasive Developmental Disorders. In Sadock, Sadock &Ruiz (Eds), Kaplan & Sadock’s comprehensive textbook of psychiatry, (9th ed, volII).Philadelphia, PA: Lippincott Williams &Wilkins.

Wing, L. (1988). The continuum of autistic characteristics. In E.Schopler & G. Mesibov (Eds.), Diagnosis and assessment inautism. Current issues in autism (pp. 91-110). New York: Plenum Press.

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