appear "spacey" or as if on drugs
fail to interact, respond, or establish eye contact with you or others
touch strangers in socially inappropriate ways
not understand even simple instructions or the presence of authority
have an extreme reaction to sound, touch, taste, or light
appear to be unexplainably angry or aggressive or in pain
cup hands over ears as if hearing is painful
act unusually nervous, passive, or hyper
spin or wiggle an object repeatedly or sift dirt, dust, etc
be preoccupied with arranging or looking at objects
shake his or her fingers, hands, arms, or head repeatedly
exhibit inappropriate screaming, laughing, giggling, or other sounds
injure himself or herself
run or climb into dangerous situations
have little or no appreciation of danger
hear or see something only after a delay of several seconds or more
be disoriented in space and time
"perseverate"--that is, repeat a simple task or movement over and over
seem to ignore you or seem to be deaf
repeat a sound or words over and over ("echolalia")
react strongly and irrationally if a pattern is interrupted
have no speech, or not be understandable
confuse "me" and "you" or other pronouns
be carrying a communication device
seem to have no or little muscle tone
walk on tiptoes
seem to have unusual skills in math, art, music, or other areas
speak more loudly than necessary
make inappropriate comments or ask personal questions of strangers
be dressed inappropriately
rock or pant, or exhibit other unusual behaviors