I agree with you De Budding; however, those things influence your thoughts while they are alive. I think when I hear "Dead people control our brains" it makes me think of large scale events in history that have such an impact it affects the way we perceive things, and in turn conditions us to think a certain way. For example, the American Revolution has instilled patriotism in all Americans and in turn gives them their own definition of Freedom (obviously this is a broad and generalizing statement). A HUGE example would be Jesus of Nathereth. From a totally historic point of view, this man has influnced countless minds after his death and continues to do so. Though he is given divine actions (which in my opinion is a matter of faith in the whole matter, but thats another thread), what he taught has, for 2008 years influence the world, which ultimately means the minds on those in it.
I suppose the problem I see in your statement de budding is that the people who influence you while living, even though they will eventually die, do not do so after death. It is also possible that they might out live you.
Going back to what Goshisdead was saying about ancestoral memory. Again I don't think it gets passed on biologically, but there is a passing down from one generation to the next. Based on this it is up to the individual involved in the family's tradition to accept the teachings or not. Speaking personally on this matter, my family has always been Jewish. I identify myself as a Jew culturally because of this, but have absolutely no belief in the religious aspect of it. I have a hard time participating in the religious holidays as my idea of what constitutes religion and cultural tradition. Though it was my Dad who taught me my family heritage, it was our ancestors who ultimately influence him and myself. So there definately is a passing of ideas down through family, but i do not beleive it is genetic.... It is a totally conscious action.