'assortive' originates from French, specifically the word 'assortir', where the prefix/root 'as-' (from Latin 'ad-') meant 'to' and 'sort-' (from Latin 'sors, sortis') meant 'lot' or 'fate'.

'assortive' changed from Old French 'assortir' (to match, arrange) into Middle English 'assort' and later produced adjective forms such as 'assortive' (and the related 'assortative') in modern English.

Initially, it meant 'to arrange or match (items or lots)'; over time it evolved into the adjectival sense 'relating to matching or similarity-based grouping,' as used in phrases like 'assortive mating.'