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Causes, Symptoms & Signs

What Are the Key Characteristics of Autism?

Characteristics of Autism include social challenges, communication differences, repetitive behaviors, restricted interests, sensory sensitivities, and a strong need for routines. Many autistic individuals may struggle with understanding social cues, maintaining conversations, or forming relationships, while also showing unique learning styles and attention patterns. Since autism is a spectrum disorder, these traits vary in combination and intensity from person to person.

characteristics of Autism

In this post, I will talk about some of the Characteristics of Autism. The key objective for me is to provide you with an overview of the wide variety of characteristics that individuals with autism display on a day to day basis.  You will also learn how these characteristics are used to make a diagnosis.

Prevalence for autism spectrum disorder is increasing.  See below a graph from Autism Speaks on how the Autism rate is rising at endemic levels:

Autism Rates Rising

In March of 2013, the Centers for Disease Control and Prevention in the United States, released that incidence rates of autism are 1:50.

Autism is a spectrum disorder, meaning the symptoms of people with ASD can range from mild to severe. Some have more noticeable traits, while others, sometimes called borderline autism, may have milder symptoms that still affect daily life.

In rare cases, individuals may develop coping strategies that mask or reduce visible symptoms over time, a phenomenon sometimes referred to as reverse autism.

Understanding the Autism Diagnosis Process

First and foremost, it is important to understand how is Autism diagnosed.

The the Diagnostic and Statistical Manual of Mental Disorders , known as the DSM, which sets the guidelines for diagnosing psychiatric disorders has recently published and released it’s most current edition: the DSM-V (Real all about DSM 5 here).  The previous edition, the DSM-IV was released in 1994. This, in conjunction with the Autism Diagnostic Observation Schedule, is an extremely powerful tool for Autism diagnosis.

dsm 4 vs dsm 5

A comparison of DSM 4 Vs DSM 5

Autism is a spectrum disorder; the symptoms of individuals with ASD will fall on a continuum.  Under the DSM-IV the term spectrum related not only the range of disorders classified under the label but also that each individual diagnosed with an ASD can present with a range of characteristics.

With the DSM-V, Rett Syndrome has been removed from the manual.  All other disorders (Autism, Pervasive Developmental Disorder or PDD-NOS, Asperger’s Syndrome, and Childhood Disintegrative Disorder or CDD) have been subsumed and will be referred to as a single classification, Autism Spectrum Disorder. The term spectrum, in this case, refers to the wide range of characteristics found in individuals diagnosed with ASD. Having ASD presented as a spectrum disorder allows clinicians to account for the variation in symptoms and behaviors from person to person.

As the DSM-V is newly released, you will continue to hear and see these terms, for example, PDD, PDD-NOS, and Asperger’s, as the autism community, adjust to the new classifications and diagnosing criteria.

Also, one of the most noted changes is that the two social domains in DSM-IV have been collapsed into one.  In the DSM4 social interaction and social communication were two different categories. In the DSM5 they are one.  The number of requirements for deficits under each diagnosing domain has also changed.  Some domains an individual will need less (for example, a language delay is no longer required for diagnosis), and in some domains, they will require more.

Under the DSM-V criteria, individuals with ASD must show symptoms from early childhood, even if those symptoms are not recognized until later. This criteria change encourages earlier assessment and screening of Autism but also allows people whose symptoms may not be fully recognized until social demands exceed their capacity to receive the diagnosis. It is an important change from DSM-IV criteria, which was geared toward identifying school-aged children with autism-related disorders, and was not as useful in diagnosing younger children, for example, preschool children.

Understanding the Characteristics of Autism

Not all children with a diagnosis of Autism Spectrum Disorder are the same.  They are their own person, and will have their own individual Autism characteristics. Autism spectrum disorder is a neurodevelopmental disorder that has 2 core areas of characteristics (plus additional criteria applicable to both areas).

  • The first core area has 2 subsections:

The first relates to impairments in Social Interaction – can range from not being able to play with toys functionally to not being able to ask a friend to play even though the child may have words.

The second, relates to deficits in Social Communication – can range from not having any verbal language and using other means to communicate, for example using pictures, or gestures, or sign language, to having verbal communication however having difficulty in comprehending others perspectives or knowing how to ask a friend to play

  • The second core area relates to restricted and repetitive patterns of behaviour, interests, or activities.  This can range from flapping of the arms, rocking back and forth, to using toys or objects in a manner not intended for.  For example, a child may turn a toy truck over and only spin the wheels, instead of driving it around on the floor. Even echolalia in Autism and Tourette’s syndrome falls under this category.
  • The third section relates to additional criteria relating to the two core areas as described: Symptoms must be present in the early developmental period (but may not fully manifest until social demands exceed limited capacities, or symptoms may be masked by learned strategies later in life).  Overall, symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning, These disturbances are not better explained by intellectual disability (such as intellectual developmental disorder) or a global developmental delay.

Social Deficits with Autism

First, let’s talk about social deficits. Difficulties in social communication and interaction can make forming friendships and understanding others challenging. Autism and anxiety often overlap here, as social challenges may trigger stress, worry, or fear in social situations, which can be seen in the following three ways:

  • Deficits in social-emotional reciprocity; behaviours range from abnormal social approach and failure of normal back and forth conversation, to reduced sharing of interests, emotions, or affect; and involves the failure to initiate or respond to social interactions.
  • Deficits in nonverbal communicative behaviours used for social interaction, ranging from poorly integrated- verbal and nonverbal communication to abnormalities in eye contact and body-language, or deficits in understanding and using gestures, to a total lack of facial expression and non-verbal communication.
  • Deficits in developing, maintaining and understanding relationships; behaviours here range from having difficulties adjusting their behaviour to suit various social contexts, to having difficulties in sharing imaginative play or in making friends; or an absence of interest in peers.

Autism and communication deficits

Eye Contact

Individuals with autism may have difficulty with maintaining eye contact, may have difficulty reading and using facial expressions, body posture and gestures.  For example, they may not respond to a “stare” that means to stop or to tone of voice.  This should not be interpreted as defiance, rather it’s that sometimes they don’t recognize what it means.

Relationships

Misinterpreted as having no relationships – children with ASD often have very strong, connected relationships with parents and primary caregivers, but they struggle with making relationships with their peers.  Lack of shared or joint attention may be the core deficit.  They don’t look to other’s to share the experience, they don’t bring others attention to their activity; for example, they don’t say “hey, look at what I am doing) and therefore they struggle to learn social behaviours.

Perspective

Children learn how to behave socially by watching others.  Children with ASD struggle with knowing that others may have a different point of view or perspective, may know or believe different things and may have different experiences.

This leads to difficulty understanding and predicting others behaviour and a lack of awareness of the impact of their behaviour on others.  They may speak in the same manner to people of all ages, with different levels of familiarity – for example, the bus driver that they don’t know in the same way they talk to a familiar family member).

Deficits in the social domain cause the individual with autism to have the inability to: Read the listener’s level of interest, detect a speaker’s intended meaning, understand “unwritten rules” or conversations, and anticipate what others might think of one’s actions.

Having a conversation

  • They may not notice when people are talking to them, therefore may not respond
  • Though they know how to talk, they may have difficulty “joining in” on the conversation
  • Some individuals with ASD may have poor eye contact or may have difficulty making eye contact at all

Non-verbal communication

They may have difficulty understanding gestures; for example, hand gestures such as waves hello or waves goodbye, or a thumbs up, understanding body language  such as shoulder shrugs, nods of approval, shaking of head in disapproval, hands crossed over one’s chest showing disinterest, smiles, etc..  As these cues may not be understood, individuals with ASD may not respond appropriately.

Routine Oriented

  • Some individuals with ASD are overly dependent on routines
  • Some individuals with ASD have a need for things to always be the same. They don’t like changes or surprises.

Examples include dressing in the same order each day going to school or work on the same route.  They may do the same activities on same days. For example, Mondays is always play gym, Tuesday is swimming, Wednesday is always a trip to the library, etc.

Making Friends

  • Children with ASD may not relate to their own age group, and sometimes prefer the company of adults.
  • Individuals with ASD may have some difficulty controlling or displaying their emotions and excitement in an appropriate manner and this can affect their social interaction with their peers.

Behavioral Deficits with Autism

behavioral characteristics of Autism

We are now going to move on to the behaviour section of the diagnostic criteria. All individuals with ASD must have or have had restricted, or repetitive patterns of behaviour, interests, or activities as manifested by at least two of the following 4 domains:

  • Stereotyped or repetitive motor movements, use of objects, or speech.  Examples include repetitive simple motor movements like twirling ones hair, lining up toys, flipping objects over, echolalia, or use of idiosyncratic phrases.
  • Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior.  Examples include, extreme distress at small changes, difficulties with transitions, rigid thinking patterns, or greeting rituals, and the need to take the same route or eat same foods every day).
  • Highly restricted, fixated interests that are abnormal in intensity or focus. For example, individuals with ASD may have strong attachment to, or preoccupation with unusual objects like fans or washing machines). Individuals with ASD may have  excessively circumscribed or perseverative interests).
  • The last domain deals with Hyper-or hypo-reactivity to sensory input or unusual interest in sensory aspects of the environment.  For example, having an indifference to pain or temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement.

Below are some of the challenges observed in behavioral characteristics of Autism – primarily related to restricted and repetitive behavior, activities, interests?

Play

  • Many people with ASD display restricted patterns of interests, therefore, may talk about or focus on only one thing, for example,  trains, or 1 particular piece of music.
  • Some individuals with ASD have unusual interests or habits, for example, obsessive interest in washing machines, motors, or a particular cartoon character.

Motor movements

  • People with autism may repeat behaviours over and over again, such as spinning, rocking, staring, finger flicking, hitting themselves, grinding teeth.
  • Individuals with ASD may display unusual postures when interacting with others; they may walk and move in a manner that is not common.

Speech

  • Children with ASD may start to develop appropriate language and then regress. They may develop language very slowly, or they may never develop vocal speech communicating only by gestures like pointing or reaching.
  • Some individuals with ASD have echolalia (this is repeating something they just heard in a non-functional manner); for example, if you ask them, “How are you today?” the individual with ASD will respond “How are you today?” instead of answering the question.

Sensory Integration

Individuals with ASD may have hypersensitivity or hypo-sensitivity to sounds, sights, touch, taste and smells. For example, fire alarms, school bells, a crowded mall, tags on clothing, smells in a restaurant all may cause distress for the individual with ASD.

Characteristics of Autism in Adults

characteristics of autism in adults

Characteristics of Autism in Adults

Characteristics of autism in adults include social challenges, difficulty interpreting social cues, repetitive behaviors, restricted interests, sensory sensitivities, and a strong preference for routines. Adults on the spectrum may struggle with forming or maintaining relationships, managing changes, and regulating emotions, while often displaying unique strengths such as attention to detail, deep focus on interests, and analytical thinking. Since autism is a spectrum, the intensity and combination of these traits vary from person to person, making each adult’s experience unique.

Additional Autism Characteristics

Besides the core social and behavioral traits, there are extra criteria for diagnosing autism spectrum disorder (ASD):

  • Early onset: Symptoms appear in early development, though they may not be obvious until social demands increase or may be masked by learned strategies.
  • Impact on daily life: Symptoms must significantly affect social, work, or other important areas of functioning.
  • Not explained by intellectual disability: Intellectual disability may co-occur with autism, but the social communication challenges must go beyond what would be expected from the disability alone.

This shows that having an intellectual disability does not automatically mean ASD is present. The deficits must be specific to autism.

The exact cause of autism is still unknown, though research points to neurological, genetic, and environmental factors.

Applied Behavior Analysis (ABA) is the only evidence-based intervention proven effective for autism. It works by studying the relationship between behavior and the environment to teach new skills and reduce harmful or unhelpful behaviors.

  • Applied: Targets socially important behaviors.
  • Behavioral: Focuses on observable, measurable actions.
  • Analytic: Uses reliable methods to determine what controls behavior.

ABA helps individuals with autism learn new skills and reduce maladaptive behaviors.

FAQ’s on Characteristics of Autism

What are the facial characteristics of autism ?

Facial characteristics of autism are not the same for everyone, and there is no single “look” for autism. Some studies suggest that certain subtle features may appear more often in autistic children, such as differences in the shape of the eyes, nose, or jaw. However, these traits are not used to diagnose autism. Autism is mainly diagnosed by looking at behavior, communication, and social skills, not facial features. Every person with autism is unique, and their abilities and appearance can vary widely.

Are there physical characteristics of autism ?

There are no specific physical characteristics that can reliably identify autism. Autism is diagnosed based on behavior, social communication, and developmental differences, not appearance. Some studies note subtle physical traits, like minor differences in facial features or body proportions, but these are not consistent or used for diagnosis. Every person with autism looks unique, and physical appearance alone cannot indicate whether someone is autistic.

What are the 3 main characteristics of autism

The 3 main characteristics of autism are social communication challenges, restricted and repetitive behaviors, and sensory sensitivities. Individuals with autism may have difficulty understanding social cues, forming relationships, or maintaining conversations. They often engage in repetitive actions, insist on routines, or have highly focused interests. Many autistic individuals also experience sensory differences, such as being oversensitive or under-sensitive to sounds, lights, touch, or other stimuli. These traits vary in combination and intensity from person to person, which is why autism is considered a spectrum disorder.

Conclusion :

Understanding the characteristics of autism helps us appreciate the wide range of experiences and abilities of individuals on the spectrum. From social challenges and communication differences to repetitive behaviors, restricted interests, and sensory sensitivities, each person’s combination of traits is unique. Recognizing these characteristics can improve support, relationships, and interventions, empowering autistic individuals to thrive in daily life.

I hope you found this post on characteristics of Autism quite helpful. Here are some additional resources that you might find useful:

Join the discussion One Comment

  • Mary L Mockford says:

    The article was most informative. I am researching resources for a relative who has an adult child displaying multi-autistic behaviors. Who is the best to make a definitive diagnosis and give the father info on associations, support groups etc.? The physical area is Seatle, WA.

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