Not only do the characters behave in quirky ways, but the movies do not go for traditional comedy. Laughs come from character and situation. A plot summary of any of his comedies could just as easily fit a dark, serious tragedy. Behind any good comedy is a real story and pain. You could write a tragic version of this guy living in West Texas.
All great comedies are like that.
The laughter is coming off the dark side. It's really romantic, more than machismo. McAvoy is his own worst enemy. His redeeming grace is that he knows it. Yet in moments that determine his fate, he is unable to control the urge to put empty gesture above his best interest.