I often get students who believe first-person language is not allowed in APA papers. This is, of course, incorrect.

Where does this misperception come from? A desire to sound more objective? Are they taught this in other classes?

Is this misperception a relic of a once-existing rule? Was there ever a time first-person language was not compliant with APA style? I cannot find it online. But perhaps someone has an old manual collecting dust they could check.