Personality vs. Consumerism

As my friend and I were talking about personalities, we got a crazy idea: does the type of person you are define the type of consumer you are?  Let me explain.  I am one of those, brutally honest, genuine people.  When I apologize, I sincerely feel sorry.  When I say that I feel bad, I am at the point of crying.  At the same time, as a consumer, I only buy genuine items, even if it means spending more money.  I refuse to download free music, download movies, or buy fake designer goods.  If I am without money, I just go without until I can buy the real thing later on.
When I asked some of my friends how they would describe their personalities and how they would describe themselves as consumers, I noticed similarities between their personalities and their purchases.  My friend who describes herself as impatient and spontaneous finds herself buying things automatically, almost without thinking.  My other friend who describes herself as aggressive and finds herself fighting for good deals at bargain sales.
As far as design, I started wondering: how do designers design their items to target the types of consumers there are? Do they take into account the personalities of their customers? Or do they design based on their own personalities and thus end up attracting consumers with similar personalities?
The designer Alexander McQueen is famous for his shows being very passionate, displaying emotional and raw power.  He was known for portraying the juxtapositions between between contrasting things. Does the fact that Alexander McQueen portrayed passionate, emotional shows mean his personality was so?
At this point, I don't think there is enough information to really make a conclusion of any kind, but the idea is pretty fascinating and I hope to explore it further in the future.

Sources:
Alexander McQueen