Is intelligence really inherited genetically?

I do really well in school and a lot of people tell me that I am talented or intelligent. I think I just have good genes, though. My great-grandfather was a very well-respected doctor in Minneapolis. My grandfather was educated at a good boarding school and then went on to get his B.A. from Harvard and his M.B.A. from Cornell. My great-uncle went to Harvard Medical School and ended up being a heart specialist at Tufts Medical School (he was one of the first people to prove the link between poor eating habits at a young age and artery blockage in later years) and was a professor at Harvard for some time.