While not specifically looking for something on the Mandela Effect a YouTube video on the subject popped up on my recommended list, because I checkout a lot of Mandela Effect videos: This video attempts to explain the phenomenon with the psychological answers. I guess it is up to viewers to decide if does or doesn't explain things.
Many Mandela Effect videos are just about slightly different words or pronunciations of the words, or part of the word dropped off at the end, or the not as popular spelling variant of a name. Hmm was the Toys R Us giraffe mascot named Jeffrey or Geoffrey? I'm pretty sure it was the not as common Geoffrey not Jeffrey. Many people might "remember" it as Jeffrey because it is the more common spelling.
Misheard lyrics: For lyrics often improper grammar is used either to make a rhyme or to keep the timing and tempo of a song consistent. Or an entire new word will be created (see Steve Miller Band: The Joker and the line "'Cause I speak of the pompitous of love"). In transposing lyrics to the written word mistakes can be made. Also how a word is enunciated or spoken, well sung rather, can be misinterpreted. For instance do you know what Manfred Mann's Earth Band is singing in "Blinded By The Light"? It isn't the crude version that people think it is. Misheard lyrics are simply that misheard lyrics. They haven't been changed by the Mandela Effect. They are just commonly misheard and the "new" version of what they say is mistakenly passed along. There is a similar thing with misquotes from movies. I won't get into those here, but many people remember a quote in a specific way that was never actually said. In many ways it is like that kids game of Telephone. Where you sit in a circle (or organized line) and someone whispers something in the ear of the person siting next to them. That person then whispers what they "heard" to the next person, That person repeats the process and on and on til the saying gets to the last person. That person then says out loud what they heard and then the original person reveals what they started things with.
There is even a Mandela Effect for the opening title speech from the Original Star Trek series. The real line is and ALWAYS has been "Space THE Final Frontier..." The Mandela Effect has changed it to "Space A Final Frontier..." It is simply a matter of pronunciation. In the Speech William Shatner pronounces the word "T-H-E' as "Thuh" not "Thee" so it sounds like he is saying "A". There are similar misunderstandings exactly like this that people have labeled as a Mandela Effect.
The phenomenon that is called the Mandela Effect could just as easily be called the "Barenstain Bears Effect".
There is at least one ME video poster who has blocked all comments on his videos, you can't even vote thumbs up or thumbs down on them. He says he is tired of people commenting on his videos. I think maybe he was getting too many negative comments and didn't like people complaining about them or the Mandela Effect. I first noticed him from a video where he has compiled about 20 minutes worth of reports of John Lennon's death and points out some of the inconsistencies of the reporting. Many of the reports were the first "breaking news" reports that were broadcast within an hour or two of his being killed. Some details of those early reports were in error. As often happens with news reporting the first initial reports have inaccurate information. Unfortunately it is the first reports that people often remember. They will remember a celebrity being arrested for something, but not that they were found innocent a few months later, or that the charges were dropped and there was never a trial.
On some other Mandela Effect video I commented on how the first initial reports often contain inaccuracies and someone tried to correct me by mentioning some details of an event I wasn't even commenting on but apparently was mentioned in the video I was commenting on. I have also been "corrected" at times with comments that basically say the same thing I had just commented, or they think I am complaining about what I commented on. This sort of thing happens to me sometimes on Facebook also. I often think I should stop commenting on social media especially videos some of which are a couple of years old.
There are some Mandela Effect believers that say if you don't believe in the Mandela Effect and mock it. You have not been effected by it yet and are from this reality. Huh? Yes most people believe that part of the Mandela Effect is that we are currently in a moment of time where multiple realities are combining together as one reality and that is why many are experiencing the Mandela Effect. They refuse to believe that they might be wrong about one difference and they defend the entire phenomenon. They also say if you don't believe in the phenomenon you don't get it and don't understand it. The one thing to understand is people are finding proof of different spellings of things or of slogans or logos that are different than what they had remembered.