what is???

my bro twists n pulls his hair when he gets anxiose . hes even tried doin mine n my moms b4 . but i dont fink he eatys it , and its part of the fact hes got autism as well coz he bangs his head to . i hope that made some sence
luv lidxxXxx

just wonderd is it classed as same thing if they chew hair but its still on head , if u get what i mean. luv lidxxXxx