Dismissive family?

Hey,

My problem is that my family (my mother and sister) are really dismissive of everything I say (unless I'm agreeing with them), and I just wonder if this is unusual and what to do about it.

I'm a philosophy student, so unsurprisingly it makes me very uncomfortable when my family members are speaking nonsense, and fairly frequently this turns into debate.

Of course I have no problem at all with my family members disagreeing with me - if they think I've said something wrong, I want them to correct me. It's just that they never stop to actually think about what I've said, they just dismiss it off-hand whenever I say anything they disagree with, and shut me down by looking at me like I'm an idiot, or being rude.

For instance, earlier today I suggested that my sister should think carefully about taking a computing course, because they often seem to be either very simplistic or very complex, and she wants something in between, and doesn't have a good track record of remaining committed to things. But when I tried to raise this point, she said I was just talking nonsense?

Similarly, a while ago I questioned my brother about his reasons for vegetarianism (I was suggesting that utilitarianism wasn't as strong a basis as it seems at first, but it turns out thats not his reason anyway), and we were discussing that, my mother finished the conversation by just attacking everything I said by giving me a nasty look and implying that I was being stupid.

I just don't really know how to deal with. I don't think I'm especially stupid - I know grades aren't necessarily an indicator of intelligence, but I got near enough 100% in all of my AS levels, which surely counts for something - so presumably it isn't just that everything I say is nonsense?

I'm not really an angry person or anything, I just find it upsetting. I always thought that members of my family were fairly intelligent, but I just feel that nothing can be challenged, or you're attacked as an idiot with no common sense (because, obviously, how intelligent you are in school hasno bearing at all on your practical intelligence - whatever that is).

Does anybody else have this experience? Am I just an ********? It just worries me - I feel like my family is the kind that would just sit there and say nothing while a holocaust passed by or whatever, and I can't change it because nobody will take anything I say seriously.