The Relationship Between Cultural Identity and Success

There's a word in Finnish called Sisu, which very roughly translates to grit. And if you're Finnish, you have the identity of someone who when things are really hard and you've given all you can and you still are falling short, you reach down inside and you use your Sisu and you do it anyway. Now, is there a connection between that kind of cultural identity and grit or non-IQ correlates with success? I absolutely think so.