▁two ▁contradict ory ▁approaches ▁of ▁cultural ▁and ▁cogn itive ▁by ▁using ▁a ▁more ▁process ual ▁approach ▁and ▁“ cross - ▁fert il izing ” ▁the ▁two . ▁ ▁He ▁engaged ▁both ▁psych ological ▁and ▁anth rop ological ▁ideas ▁to ▁combine ▁the ▁two ▁approaches ▁effectively . ▁ ▁He ▁believed ▁that ▁the ▁existing ▁assumptions ▁of ▁cultural ▁uniform ity ▁on ▁the ▁eth n ographic ▁analysis ▁of ▁categories ▁were ▁not ▁correct , ▁as ▁variation ▁was ▁evident . ▁He ▁used ▁the ▁animal ▁class ifications ▁of ▁the ▁N ua ulu ▁people ▁to ▁present ▁his ▁point . ▁ ▁His ▁point ▁being ▁that ▁in ▁regards ▁to ▁the ▁class ifications ▁of ▁animals ▁made ▁by ▁the ▁N ua ulu ▁people , ▁one ▁must ▁pay ▁attention ▁to ▁different ▁types ▁and ▁context s ▁of ▁variation . ▁According ▁to ▁Ellen , ▁“ In ▁a ▁single ▁body ▁of ▁data ▁there ▁may ▁be ▁variation ▁according ▁to ▁many ▁criteria ▁which ▁are ▁often ▁cross - cut ting ▁and ▁rein force ▁each ▁other ▁irregular ly .” ( 1 9 7 9 : ▁ 3 3 7 ) ▁There ▁are ▁various ▁reasons ▁and ▁ways ▁people ▁class ify ▁and ▁categor ise ▁as ▁a ▁result ▁of ▁both ▁culture ▁construction ▁and ▁the ▁cogn itive ▁approach . ▁Ellen ▁states ▁what ▁he ▁bel ieves ▁to ▁be ▁in ev itable ▁is ▁the ▁fact ▁that ▁the ▁“ products ▁of ▁class ifying ▁behavior ▁reflect ▁the ▁immediate ▁social ▁conditions ▁of ▁the ▁situations ▁in ▁which ▁they ▁are ▁used ” ( 1 9 7 9 : ▁ 3 3 7 ). ▁ ▁In ▁other ▁words , ▁factors ▁such ▁as ▁environment , ▁culture ,