Surely not by our bourgeois standards. Given the human brain and the human adaptability which is a gift from the most creative of us over the past 150,000 years, I think it's impossible to say what is "natural" for people other than to claim that it is natural for humans to make things and to live in cultures.
Are Savages Noble? The parts about war and sex (naturally) are especially interesting. So I guess war and sex are natural, too.