Loss of Colexification of ‘hand’ and‘five’ in Austronesian Languages

Many Austronesian languages employ similar words for the concepts ‘hand’ and ‘five’. Indeed, (partial) colexification of these two meanings is generally reconstructed back to Proto-Austronesian. However, a number of Austronesian languages do not colexify ‘hand’ and ‘five’, raising the question of what drives such lexical splits. Based on a sample of 812 Austronesian languages, I identify 465 languages (57 percent) as not exhibiting colexification of ‘hand’ and ‘five’. I find that terms for ‘hand’ are often subject to replacement, whereas terms for ‘five’ are generally stable throughout the family. The replacement of ‘five’ has occurred primarily in languages in which the inherited decimal counting system has been lost and the numerals ‘six’ through ‘nine’ are no longer unanalyzable monomorphemic words. This suggests that lower numerals like ‘five’ are less likely to be stable lexical items when they do not lie somewhere in the middle of a series of underived number terms.