Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions.

• Lack of greeting 1
• Lack of imitative social play13
• Lack of joint attention4
• Lack of shared enjoyment with others9
• Lack of spontaneous affection4
• Lack of spontaneous imitation1
• Not easily comforted1

Deficits in nonverbal communicative behaviors used for social interaction, ranging, for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.

• Flattened affect (lack of facial expressions)10
• Inability to follow a point1
• Lack of attention to voice4
• Lack of expressive language17
• Lack of eye contact16
• Lack of gesturing1
• Lack of pointing to request2
• Lack of pointing to show1
• Lack of receptive language2
• Lack of response to name11
• Unusual Point1

Deficits in developing, maintaining, and understanding relationships, ranging, for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to absence of interest in peers.

• Aggression1
• Lack of inhibition1
• Lack of interest in other children6
• Lack of Mastery Motivation2
• Lack of pretend play7
• Prefers to be alone2

Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypies, lining up toys or flipping objects, echolalia, idiosyncratic phrases).

• Complex mannerisms / stereotypes5
• Hand and finger mannerisms6
• Immediate echolalia3
• Unusual gait2

Insistence on sameness, inflexible adherence to routines, or ritualized patterns or verbal nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat food every day).

• Insistence on sameness2
• Preference for structure1
• Selective eating3
• Tantrums2

Highly restricted, fixated interests that are abnormal in intensity or focus (e.g, strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interest).

• Inappropriate play with toys10
• Unusual preoccupations9
• Unusual sensory interests17

Hyper- or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement).

• Negative reactions to sensory stimuli3
• Self injurious behavior1
• Sensory Interests1