Although the entire film and book series of Harry Potter takes place within the wizarding world that is hidden within our own, there are still a lot of normal people who exist and populate this fictional universe. In Harry Potter-speak they're called muggles, but we would just call them people who don't have magical powers. And these muggles find themselves entwined with the wizarding world for all manner of different reasons.
Because the wizarding world and muggle world so often collides, it's interesting to look at the muggles in the wizarding world through the lens of our normal human existence. So then, if the muggles of the Harry Potter universe were to do something we real life muggles often do, for instance, the MBTI personality assessment, where would they all fit in? These are all of the most well known muggles in the Harry Potter universe, along with their MBTI type.
10 Robert McGonagall - ENFP
Not a lot is known about Professor Minerva McGonagall's muggle father, Robert McGonagall Senior, but everything that we do know about him makes him seem like a pretty badass guy. When he fell for Minerva's mother Isobel, the pair decided to elope against their parent's wishes.
And although Isobel didn't actually fess up to being a witch until their first daughter Minerva began showing signs of magical power, Robert took the revelation in stride and his opinion of his wife didn't change at all. That's why Robert seems very much like the free spirited ENFP, also known as the Campaigner.
9 Mr. Granger - ESTJ
It can be pretty hard to judge a parent based solely on the personality of their child, but when that child has a personality as strong as Hermione Granger it's considerably easier.
One of the few things we do know about Hermione's dad is that he is a dentist, so presumably he must be a bit extroverted to have such a profession. And given that Hermione seems to be a pretty strongly ESFJ personality, also known as the Executive personality type, it seems safe to assume that her dad very likely falls into the same category as she does.
8 Mrs. Granger - ESTJ
Again, given how intense Hermione's own personality seems to be, it also seems safe to assume that she was raised by two people who have very similar personalities to her own.
The Executives of the MBTI are extremely organized and traditional people who do their best as leaders, and they're never really afraid of a challenge. They can seem overly rigid at times, but the reality is that they just love for things to be orderly, but if they're thrown for a loop then they can not only handle it, they can lead others as well.
7 Aunt Marge - ENTJ
Aunt Marge is an absolutely repulsive woman, and she somehow is so rude and cruel that she almost makes the rest of the Dursleys look downright polite. But one thing that can't be denied about Marge is that she is an extremely commanding woman, which is why she is likely a ENTJ personality type, also known as the Commander.
Commanders are extremely strong willed people who can come off as aggressive to many other personality types, and they are leaders, not followers. Marge seems like the type who can't be convinced of anything, so it seems like a perfect fit for her.
6 Mary Lou Barebone - ENFJ
The ENFJ personality type is often called the Protagonist, which on it's face seems like the absolute last word that you'd use to describe someone like Mary Lou Barebone.
However, when you look at her character from a different perspective, it's easy to see how she fits into that personality category. We all know that she's a living nightmare, but in her own mind she is a hero who is trying to save the world from sin. And she is an undeniably compelling individual who knows how to get things done and convince people of her own perspective.
5 Tobias Snape - ISTJ
By all accounts, Tobias Snape was a pretty unpleasant and unkind individual, so much so that by contrast even someone as severe as Severus might look better. He was a neglectful father and abusive husband, and it seems like nothing and no one truly caught his interest.
It seems like Tobias would have fallen into the ISTJ personality type, better known as the Logistician. Logisticians are extremely regimented and reliable, and they care more about facts and practicality than nearly anything else. They can be extremely responsible, but their worst versions can be quite unpleasant to be around.
4 Vernon Dursley - ENTJ
Much like his awful sister, it seems like Vernon Dursley is best fit in the category of the ENTJ, also known as the Commander. Commanders are natural born leaders who hate to follow, and although Vernon lacks the intelligence to get anyone to actually follow him outside of his wife or son, he certainly isn't ever going to listen to what someone else has to say and follow their directions.
Vernon is extremely traditional and doesn't like to venture outside of what he already knows, so it's easy to see that he is a Commander who is just too afraid and stupid to fulfill his natural personality type.
3 Dudley Dursley - ESFP
You might think that in order to fall into the category of the ESFP, also known as the Entertainer, that you'd actually have to be entertaining, but Dudley Dursley proves that's not the case.
Dudley at least seems to entertain his bully lackeys, and his constant histrionic behavior certainly matches the energy level of the Entertainer group quite well. Despite being raised by absolutely nightmarish parents, Dudley at least has enough inner emotion to empathize with even those he hates on some small level. Perhaps as an adult Dudley was able to channel his natural Entertainer nature in a more positive way.
2 Petunia Dursley - ENTP
The ENTP personality type is better known as the Debater. And if there is one thing that Petunia Dursley seems to be extremely consistent in, it's her ability to contradict whatever anyone else says, does, or thinks.
Unfortunately not a lot of thought actually goes into Petunia's contrary nature, she seems to disagree with everyone simply because she likes disagreeing with people. The best Debaters are actually quite intellectually curious and very thoughtful, but Petunia clearly prefers to isolate herself from everyone that she has any dislike towards or conflict with, so she embodies all of the worst parts of the ENTP.
1 Tom Riddle Sr. - ESTP
ESTP personality types are often times called the Doers, and it seems like the elder Tom Riddle was definitely all about his social life and social standing. ESTP's can be quite spontaneous, but their desire for freedom can trump nearly everything else.
Obviously Tom Riddle never loved Merope Gaunt, however the fact that he abandoned her and his own son almost immediately after the love potion he was under the influence of wore off is still a bit of a shock. Most people would at least stick around for a little while, but Tom's instant willingness to leave them behind just goes to show how much he valued his own freedom from others.