Dissociative identity disorder

- [Instructor] Dissociative Identity Disorder, which was formerly called Multiple Personality Disorder, describes cases where two or more distinct personalities or distinct identities seem to exist within a single body. And both of these identities have some kind of influence on that person's thoughts or behaviors. These identities are distinct from one another. They have their own mannerisms. They can have different emotional responses. And there can sometimes even be physical changes, and I'm going to put physical in quotes here, because I don't actually mean that there are changes in body parts in any way, but there have been some cases where researchers have described that the distinct identities have different handedness. One identified as being left handed, and the other identified as being right handed. There are also cases where one of the personalities, typically the original personality, denies the existence of the other ones. So, it isn't actually aware that these other distinct personalities exist within that person. So how would something like this come about? Research indicates that individuals who've been diagnosed with Dissociative Identity Disorder have a history of child abuse, or some other kind of extreme life stressor. And there are a lot of different theories as to how this could happen, but they all seem to center on a central idea, which is that under cases of extreme stress, a person's conscious awareness disassociates, or separates from, certain painful memories, or thoughts, or feelings. How common is Dissociative Identity Disorder? How often do we see it in the population? And the answer is, Dissociative Identity Disorder is extremely rare. In fact, I think that one of the only reasons that people are aware of this disorder is because it winds up in movies or books as a plot point or a plot twist. And we also know about it because we sometimes hear about it in the news. And by that, I mean that it's been popularized by extreme and sometimes fake cases. If you have some time, you can look up the case of Kenneth Bianchi, who was known as the Hillside Strangler. He was a man who claimed that his crimes were actually the result of a different personality. It was later determined that this was not the case. However, it did put this disorder in the news. Unlike the other disorders that we've talked about so far, there's actually a fair amount of controversy that surrounds this one. And part of that controversy has to do with how rare it is. Because as rare as it is in North America, in the United States, it's even more rare outside of America. This leads some scientists to wonder whether or not it's some kind of cultural construct instead of a real disorder. Others wonder if this is a disorder than can be induced by therapists. So, maybe a therapist who knows about this disorder, and suspects that someone might have it, might say things like, "Do you ever feel like there is another part of you? "Maybe a part of you that you aren't always aware of?" And then from there, that can be taken even further. They might ask something like, "Does this part have a name? "Can I speak to this part?" And in response to this, the individuals who are seeking therapy might intentionally or unintentionally play along with what the therapist is saying. This brings up another interesting point about personality changes and about role-playing. Because in some way, we actually all have multiple personalities. The person who we are when we're in private is different from the person who we are when we're with our grandparents or our friends. We all play different roles in life, and we're expected to play different roles. We step up to them and we play along, and we don't even think about it. That's just how we act in different situations. So, maybe some people, in situations of extreme stress, might kind of lose themselves in these different roles, sort of the same way that an actor might lose themselves in a part. So these multiple personalities, these supposedly distinct identities, could be some kind of extreme form of role-playing, maybe even one the individual isn't aware of. And at this time, the answer doesn't seem to be completely clear.