It’s possible to pretend to be smarter than one is… Like when one twin takes a test for another twin who wasn’t as prepared for the test.
Or if a seventh-grade sibling does a first-grade sibling’s homework.
Little Froggie could really be Big Froggie giving Little Froggie the credit.
Though that’s technically fraud.
You’re talking about something else.
What about someone who has a dissociative disorder and speaks from one psyche at times (with profound intelligence), while mostly living from a less cognitively developed part most of the time?