Study published in Autism journal demonstrating that naïve observers can identify autistic children as socially awkward from exposure as brief as one second.
"To test how fast these judgments emerge, adults viewed autistic and nonautistic children for one second or three seconds, or saw a single still frame. Even one second was enough for naïve observers to label autistic clips as more 'socially awkward,' and that held across audio, video, and still image"