We all know that our ancestors have a lot of affect on us.  On what we look like, how we behave, and what diseases we are likely to get.  This is all the result of heredity and that which is passed on to us through genes.  But there is more to it than that.  
    Our parents affect us more than other ancestors because they raise, tell us what to do, what to eat, etc.  As I am writing this article (1/30/2010), it is snowing here and I am going to bake an apple crisp later.  Why?  Partly because I like apple crisp but also, because when I was a child, my mother always baked something on days with bad weather so I always want to bake something when it snows.
    But our parents are not the only ancestors that affect us.  We actually have the thoughts and minds, in a manner of speaking, of our ancestors going back many generations within our brains.  Sometimes, without our being aware of it, an ancestor from several generations back will send ideas to our conscious mind and affect our behavior.  In fact, I think that when emotional and mental trauma causes the phenomena known as multiple personality disorder, what is really happening in many, if not all, cases, is that the person is withdrawing from reality and that is allowing a strong-willed ancestor, or sometimes more than one, to come forward and take over.