Does level difference affect agro radius?

Solution 1:

Yes, the higher your level compared to theirs the closer you can get without drawing aggro.

I see this whenever a much higher friend helps me out, and effortlessly runs through a scattered group that I cannot run through without drawing aggro.

Also, some mobs have larger aggro radiuses than others. I suppose the mob type is supposed to have higher sense abilities when that is the case.