When it comes to cleanliness, the Swiss genes win. Public restrooms are much, much cleaner on the Swiss side than the French side. And we are still laughing about the small plaque in the hotel bathroom that stated they use "Swiss Clean" products.
But when it comes to driving, the French genes dominate all the way.
The cars would generally drive at least 20 kph over the speed limit on the highway. But periodically you would see everyone brake for no apparent reason and go exactly the speed limit. We theorized the drivers had memorized the location of the cameras. Around Zürich, most everyone drives exactly the speed limit regardless of where the cameras may be.
And when we would stop for pedestrians in the crosswalk, which would be unthinkable to fail to do in the German-speaking area, two things would usually happen. First, we would be nearly rear-ended by the car tailgating us who didn't expect us to actually stop for a pedestrian. And then the pedestrian would look at us in shock before quickly waving and darting across the intersection.
There are likely many more differences between the French-speaking and German-speaking Swiss, but those were the most obvious to the casual observer.