Publication Date

Fall 2021

Advisor(s) - Committee Chair

Dr. Lisa Duffin-Rexroat (Director), Dr. Carl Myers, and Dr. Sarah Ochs

Degree Program

Department of Psychology

Degree Type

Specialist in Education


The prevalence of autism spectrum disorder (ASD) in young children has been increasing over the past several years. Receiving individualized interventions at an early age (before age 3) drastically shifting the developmental trajectory of a child with ASD in a more positive direction, as well as improving the child’s level of functioning, showing the importance of early intervention for a child with ASD. To receive early interventions, a child must first be diagnosed with ASD. Some research suggests that characteristics of ASD can be seen in children by the time they are 24 months. However, research also shows that most children do not receive a diagnosis of ASD until they are almost four. One large reason for this gap of when characteristics are present and when a diagnosis is made could be due to the overlap in characteristics that is seen at the age of 24 months in children with ASD and children with motor, communication, or social delays. A systematic literature review was conducted using the PRISMA flow diagram to develop a comprehensive list of characteristics that can differentiate ASD from other developmental delays at 24 months. Seven key characteristics that can differentiate ASD from developmental delays are identified and discussed.


Child Psychology | Disability and Equity in Education | Early Childhood Education | Educational Assessment, Evaluation, and Research | School Psychology

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