Research investigating expressivity in children with autism spectrum disorder has reported flat affect or bizarre facial expressivity within this population; however, the impact expressivity may have on first impression formation has received little research input. We examined how videos of children with autism spectrum disorder were rated for expressivity by adults blind to the condition. We further investigated the friendship ratings given by 44 typically developing children to the same videos. These ratings were compared to friendship ratings given to video clips of typically developing children. Results demonstrated that adult raters, blind to the diagnosis of the children in the videos, rated children with autism spectrum disorder as being less expressive than typically developing children. These autism spectrum disorder children were also rated lower than typically developing children on all aspects of our friendship measures by the 44 child raters. Results suggest that impression formation is less positive towards children with autism spectrum disorder than towards typically developing children even when exposure time is brief.