'approbativeness' originates from Latin, specifically the word 'approbatio' (from 'approbare'), where the prefix 'ad-' (in the assimilated form 'ap-') meant 'to/toward' and 'probare' meant 'to test, to approve'.

'approbatio' passed into Old French as 'approbation' and into Middle English as 'approbacioun/approbation'; the adjective 'approbative' (meaning 'expressing approval') developed from this root, and the noun 'approbativeness' was later formed in Modern English by adding the suffix '-ness' to 'approbative'.

Initially related to the act or expression of approval ('approval, commendation'), the term evolved to also denote a personal disposition toward seeking approval ('a tendency to seek praise or approbation').