late Middle English: from Old French sorte, from an alteration of Latin sors, sort- 'lot, condition'
The construction these sort of, as in I don’t want to answer these sort of questions, is technically ungrammatical. This is because these is plural and needs to agree with a plural noun (in this case sorts rather than sort). The construction is undoubtedly common and has been used for hundreds of years, but is best avoided in formal writing. See also kind1 (usage).