Correct me if Im wrong but its only recently that Europe (in modern times anyway) had to deal with a large influx of immigration from vastly different races, cultures and religion. To be French has always meant that you are a Frenchman and in addition to sharing certain cultural values with your countrymen it also meant sharing DNA as well.
OH MY GOD !!
Immigration in France is as old as it is in the US ! "something based on DNA " ???

From where comes such a weird idea ? It sounds really hmm... well.
Since the 18th/19th century, France has always lived
massive waves of immigration. European people aren't homogenous, they are totally mixed. Pick any belgian, french, dutch, german, italian and you can find for them ancestors coming from the whole Europe or even farther !
Actually, people coming in France had been germans and dutch, then poles, hungarians and from other Eastern countries, then russians and jews, then spaniards and italians, then asians, caribbeans and portuguese, then arabs and africans. It has never stopped ! Being French has never meant being called "Dupont" or "Durand" !

Statistically, 50% of french people have at least one grand parent born in a foreign country (I'm part of these 50% by the way).
The French litemotive about immigration has always been to consider any newcomer as a full member of the French communauty (cause we consider that whatever are our difference, we all belong to one communauty, the french communauty). Of course, it's an ideal, but it worked very well and the results had always been great. Naturally, at each wave of immigration, they've been some tensions. For example, as weird as it seems, Parisians felt invaded by the brittons and the germans in the middle of the 19th century. Few years later, all tensions disappeared as naturally as they firstly appeared. That's what Kinniken considers as french "integration". It's the system about
living together I was talking about.
I'm always amazed to find some american people considering all other people in the world as being necessarily homogenous. That's really surprising. For example, someone didn't believe I could be blond haired because I was french and french are all black haired (lol !

).