Why people have different personalities?
491189
Genetic reasons, if we are in similar place, society also.
861146
different kinds of people, mixed kinds of people with different temperaments, colors, etc
1034140
different for different people
969042
i like everyone with a personality not what they categorise themselves as
147808
a- multiple personalities (true ones, not fakers) are a one in a million chance.\nb- since we dont understand the nature of a multiple (are they seperate spirits?  we know they have no knowledge of each other, and that even brain waves are different, but are they even the same person? [the body does not make the man, but the spirit]) this question cannot be answered by the human mind
91637
yeah, some people are just weird like that... it could be a clsh of personality... you hear often how opposites attract and when others don't get along because they are sooooo much alike... that's the way love goes
463562
When you were born does not determine personality.  Heredity and environment determine personality, regardless of what astrologists try to tell you.
55979
Personality has a lot to do with it. A larger person with a great personality is better off than a small peson who sucks.
518492
u cant categorize people into one thing.  every single person is different and we all have our own preferences.  some do some dont
1052400
It's all about personalities. Some do the right thing and their happy with it. Others don't, and they're happy with that. some are raised to do the right thing no matter what, others aren't. It's all about conciences too; some do the right thing, but don't reap any benefits from it, so they do wrong and life seems better, others do the opposite, and some just can't catch a break no matter what they do.
952484
Clash of personalities.
599375
The psychology world believes it has to do with the fact that the sex organs which dictate hormones, which dictate a lot of an indivduals features is the problem. Your mind developes after the sex organs so if there is a slip in the gene expression compared to the rest of the DNA then u have a person in the wrong body.
392275
Actually the name's been changed to DID, or Dissociative Identity Disorder. Good question, in that, it is a subject of great professional debate. The crux being, if the person truly has completely distinct multiple personalities, why do they often seem to know they have them before anyone tells them. If the personalities are completely distinct, then how do they know who each personality is ,and how they act before speaking to a professional. Generally, friends and family members wouldn't have the terms or knowledge to describe each personality to them. As of now. it's mostly seen as protection for an exceedingly weak ego, and many psychology professionals don't buy DID as it's been classically presented.
562901
May be that some people have a bit of differences and therefore tend to get nervous and out of control!?
325318
Everyone has their own interpretation of normal, and there are also standards - unwritten but more developed over a period of time, based on religion, morals, ethics, and more commonly, judgemental people who decide that their way(s) is/are normal, and others who don't conform to their way of living are not normal.  There are also social and psychological "norms" that define "different" or abnormal behavior.
337719
they don't actually know that they act crazy or weird when they want to get attention. they don't have enough self-confidence to show who they trully are or don't like themselves for who they are, so they act totally different from their real personality. they try to act like someone who they feel will be accepted by people around them and that makes them crazy.
100125
Definitely!  I think because we play so many different roles in life, sometimes we feel like different people.  It is important though to keep in touch with your own personal values, morals and priorities so that when you "people switch" you are still you!