I think the unaltered/altered debate (for me, anyways) boils down to this...

The people who have unaltered pets because of laziness or machoisms, are not likely responsible owners anyways. These are likely the same people whose dogs who are chained 24/7 with little to no socialization...teased and tormented by the neighborhood children, fed crappy food (and yes, I do believe that sometimes there is a correlation between crappy food and some types of behavior problems) encouraged to be "tough" etc.

Then there is another class of owners with unaltered dogs - people who show, people who do performance and feel that their dogs need to be "complete" to perform at their best, people who cannot alter their dogs because of some health reason (such as myself with my dane). These are responsible owners who are not apt to contribute to the other qualities that can lead to bad behavior.

There's no doubt in my mind that hormones can lead to aggression..but a responsible owner knows their dog well enough to head it off before it reaches a dangerous point. An irresponsible owner laughs, ignores it, or thinks it's cool until it's too late.

/ramble