I'm 1/8 Spanish, why don't I look very Spanish?

I'm 1/8 Spanish (Spain), I noticed that I don't look very Spanish, for instance, my mouth and lips don't look like a Spaniard's would, I have more in-line lips (bottom and top lips line with each other) while I noticed that many Spaniards have an upper lip that goes out farther than the bottom one (like an overbite would look). Why don't I look very Spanish, am I right on this essment of lips? Help? Do I not look very Spanish because I'm mixed with other stuff? Help?