I remember that split personality people were a big thing on the talk shows (another big thing was spoon-bending type psychics) when I was a kid in the 1980s. Later it turned out that pretty much all the well-known split personality stuff were hoaxes and scams.
Like there was this guy they had on talk shows who had 15+ personalities and the interviewer would ask to talk to specific ones, and they have one personality who for example was a "9 year old black kid from the Bronx" and another which was an old white lady with some other accent, things like that, and the interviewer would talk to all of them, and take it seriously. But then again they used to have mediums who'd, for example, be brought on to talk shows in robes and channel Xebu from the Omnicron Nebula with a message for mankind. Yeah, exactly what super-intelligent telepathic aliens would do: get a link with a little old lady, then go on Oprah.
Maybe individuals were skeptical but the media at least bought into all this stuff. It was the same era of the moral panic about satan-worshipping kindergarten / pre-school teachers and devil-worshipping D&D player suicides scares as well, and it was the era of using repressed memory hypnosis to uncover abuse (later they found out it wasn't repressed memory hypnosis at all, the hypnotizers were more like implanting the abuse memories themselves). The 1980s was a weird mishmash of new-age bullshit, evangelical bullshit, and weird psych bullshit. Those people probably thought the TV show "Touched by an Angel" was a documentary.