▁of ▁the ▁Los ▁Angeles ▁Times ▁wrote ▁that ▁she ▁did ▁not ▁know ▁how ▁histor ically ▁accurate ▁the ▁movie ▁was , ▁" But ▁this ▁is ▁film ▁making , ▁not ▁carbon ▁d ating , ▁and ▁it ▁seems ▁that ▁every ▁piece ▁of ▁magic ▁and ▁the ▁skill ▁of ▁every ▁craft ▁has ▁been ▁used ▁to ▁free ▁our ▁imagination , ▁to ▁let ▁it ▁so ar ▁with ▁the ▁film ▁to ▁see ▁what ▁life ▁may ▁have ▁been ▁like ▁ 8 0 , 0 0 0 ▁years ▁ago ." ▁Paul ine ▁K ael ▁of ▁The ▁New ▁York er ▁wrote , ▁" It ' s ▁almost ▁impossible ▁to ▁guess ▁what ▁the ▁tone ▁of ▁this ▁a pe - man ▁love ▁story ▁( based ▁on ▁a ▁French ▁novel , ▁by ▁J . ▁H . ▁Ros ny , ▁Sr .) ▁is ▁intended ▁to ▁be . ▁Are ▁we ▁meant ▁to ▁laugh ▁at ▁the ▁gam iness ? ▁At ▁the ▁men ' s ▁were w olf ▁fore head s ? ▁( Th ick ▁hair ▁spr outs ▁about ▁an ▁in ch ▁above ▁their ▁e y eb rows .) ▁The ▁director , ▁Jean - Jac ques ▁Anna ud , ▁seems ▁to ▁be ▁willing ▁for ▁us ▁to ▁laugh ▁but ▁not ▁sure ▁about ▁how ▁to ▁tell ▁us ▁when ." ▁ ▁Scient ific ▁response ▁In ▁an ▁ess ay ▁for ▁the ▁journal ▁American ▁Anth rop ologist , ▁Brown ▁University ▁lingu istics ▁professor ▁Philip ▁Lie ber man ▁described ▁as ▁" abs urd " ▁the ▁mixture ▁of ▁different ▁levels ▁of ▁adv ancement ▁among ▁different ▁tribes ▁living ▁in ▁close ▁proxim ity . ▁Lie ber man ▁pointed ▁out ▁that ▁it