The purpose of this study is to investigate whether a social initiation motivation intervention (SIMI) focused on training children with ASD to initiate to peers during structured play activities will result in more frequent initiations to typically developing peers during free play. The SIMI approach under investigation uses behavioral strategies based in Applied Behavior Analysis and Pivotal Response Treatment to motivate children with ASD to initiate to peers. Children with ASD will be randomly assigned to either the SIMI or a waiting list. Treatment will be provided for 8 weeks in the context of a weekly social skills group.

Inclusion Criteria:

1. age 4.0 to 6.11 years;
2. diagnosis of Autism Spectrum Disorder
3. without intellectual disability
4. stable community treatments four weeks before and throughout the trial.

Exclusion criteria:

1. diagnosed severe psychiatric or genetic disorder or medical problem;
2. severe disruptive behavior that would interfere with peer interactions