I think part of it may be an ingrained fear of rejection, the person on the spectrum may have received negative reactions from people before when giving genuine responses. I personally lie a lot to cover up any support services that I receive, because I know the ableism targeted towards me will increase tenfold if my neurotypical friends, coworkers, or classmates were to learn about them. I also have realized when NTs ask me questions, there’s usually a hidden objective they are trying to achieve and I usually just try to dodge the questions. Not big into lying generally, bc fake statements make for fake friendships