I'd disagree a bit in here, as how does driving a bigger car in this case 4WD which can be a handfull to drive, make people take more risks? I know that I take the corners much faster and change lanes more frequently in my small hatchback than when in "trol" as it is more stressful/more work to keep the "trol" on the road.
Taking corners fast is only one of many risks. Many 4x4 drivers will change lanes on top of someone with the 'i'm bigger than you' attitude; pull out in front of people, tailgate... general intimidation tactics. I have noticed this happen MUCH more often when i'm in the GF's corolla - particularly tailgating

. Funny that it never really happens when i'm in the troll...
I hate tailgaters, particularly 4x4 driving ones - and WAAAY too many do. A little 'rolla will pull up MUCH faster than a troll, as a mate of mine recently found out

.
That's not to say that the majority do all of the above, just that a higher representation of 4x4 drivers drive like this compared to drivers of smaller cars.
But i completly agree with the rest of your statement.