ger ’ s ▁synd rome . ▁Due ▁to ▁incons isten cies ▁in ▁diagn osis ▁and ▁how ▁much ▁is ▁still ▁being ▁lear nt ▁about ▁aut ism , ▁the ▁most ▁recent ▁D SM ▁( DS M - 5 ) ▁only ▁has ▁one ▁diagn osis , ▁aut ism ▁spectrum ▁dis order ▁( AS D ), ▁which ▁en comp ass es ▁each ▁of ▁the ▁previous ▁four ▁dis orders . ▁According ▁to ▁the ▁new ▁di agnostic ▁criteria ▁for ▁AS D , ▁one ▁must ▁have ▁both ▁def ic its ▁in ▁social ▁communication ▁and ▁interaction ▁and ▁restricted ▁repet itive ▁behav iors , ▁interests ▁and ▁activities ▁( R R B s ). ▁ ▁AS D s ▁continue ▁to ▁be ▁over ▁four ▁times ▁more ▁common ▁among ▁boys ▁( 1 ▁in ▁ 3 7 ) ▁than ▁among ▁girls ▁( 1 ▁in ▁ 1 5 1 ) ▁in ▁diagn osis ▁due ▁to ▁the ▁a for ement ioned ▁ability ▁to ▁mask ▁better ▁than ▁males , ▁and ▁they ▁are ▁reported ▁in ▁all ▁ra cial , ▁eth nic ▁and ▁so cio e conom ic ▁groups . ▁Studies ▁have ▁been ▁conducted ▁in ▁several ▁contin ents ▁( As ia , ▁Europe ▁and ▁North ▁America ) ▁that ▁report ▁a ▁pre val ence ▁rate ▁of ▁approximately ▁ 1 ▁percent . ▁A ▁ 2 0 1 1 ▁study ▁reported ▁a ▁ 2 . 6 ▁percent ▁pre val ence ▁of ▁aut ism ▁in ▁South ▁Korea . ▁ ▁Fre quency ▁Although ▁inc idence ▁rates ▁measure ▁aut ism ▁risk ▁directly , ▁most ▁ep ide mi ological ▁studies ▁report ▁other ▁frequency ▁measures , ▁typically ▁point ▁or