Thats not quoting parrotlets though I know I said that but it isnt a quote.I know both are aggressive but I have yet to see an aggressive parrotlet and I do have a little experience with parrotlets I had one for a few days remember and I see Wasabi almost everyday.

Curing aggression toward the owner is frequently a matter of training the human not the bird lol. We humans don't automatically understand that most of the time when we get bitten it's because we didn't pay attention to the bird's feelings and body language, and did something they didn't like. We're less likely to get bitten if we don't do something that makes the bird want to bite us, and AVOID THE BITE is a major principle of reducing aggression problems.

There are some situations where training can help reduce aggression. For example if you've got a cage-territorial bird that always attacks you while you're changing the food and water, you can teach it to go to a different part of the cage while you're doing this job. You haven't taught the bird to stop being aggressive, but you've reduced the provocation.

I actually did use training once to reduce aggression between birds. Back when my only two birds were Vlad and Geezer, there was a specific situation that occurred when they were both on top of the cage together (me wanting to give them head scritches maybe?). Geezer was kind of a bully, and he would always attack Vlad in this situation but I wanted them to share. So I would put them on the cage (not too close together) and Geezer would get rewards as long as he didn't make an aggressive move. If he made an aggressive move, I took him off the cage top and ignored him for a few seconds, and Vlad got the treats. This actually stopped the aggression in that particular situation. It didn't stop it anywhere else though. I don't think there's a way to teach a bird to never be aggressive at all, but it can work in small, specific situations.