Men tend to be more obsessed rather than aggressive. The aggressive part comes from how they are raised rather that by their genes.
And a man can show obsession by talking endlessly rather than by demonstrating aggression.
However men are less likely to have a grudge and therefore any aggression they do show isn't likely to be permanent. But it is likely to be instant. But this factor can be found on some women as well.
So not everthing is a specific rule between the genders. It is really a general rule.
I was speaking generally (have been known to be a little aggressive myself sometimes but don't tell anyone, they may not notice lol) but some of the comments on this site get really aggresive rather than obsessive and at that point the ladies seem to leave the discussion.
Perhaps this is why we have so much misunderstanding between our various countries? Surely better understanding can only come from opening your mind and accepting the other person has a point of view even if you don't agree with it, rather than simply arguing your point over and over again.