Greta started showing guarding instincts within the first month of getting her. We were on one of our usual walks and a jogger appeared about a block away (keep in mind this was her first jogger to see so i imagine she was like "wtf?"....the person was moving pretty quickly and Greta immediately got in front of me and between myself and jogger, stood tall, uttered a low growl and started barking up a storm. Since then she's gotten a lot better about recognizing that a jogger isn't something i need protecting from but she still watches with the "stare" when things are coming towards me. Even if someone crosses the street a block away, she will watch them intensely. When out and about like at petco or somewhere similar if someone comes up to me she can be friendly, sometimes aloof and sometimes full-on guard mode. All seems to depend on the person, she's loves children and the majority of women but most men she's a bit shy, and if they're big guys she will stand between us and if they approach without my approval she'll bark really loud and sometimes even give them a low growl. She keys in on my attitude towards them quite a bit, if i show them friendliness and a positive tone she perks right up with happiness but if its someone that I don't like she knows and will let them know immediately. She's extremely protective of children, my own and others. One time we were at the park (not even the dog park part) at the playground. My daughter was playing with a friend while I was just standing around with the other child's mother watching them have fun. A very large (built like a tank) man popped out from his truck and yelled out "Is that a pit?!?" and i admittedly got a little nervous. I'll give you a little background information to explain this reaction from myself. For years, whenever i walked Dharma (My APBT) i would have random guys come up to me, start asking about them and then ask if i'm going to fight her and that i should....of course i would react very negatively about this (Obviously) and let them have it verbally. Living around Atlanta I get that on occasion, i'm guessing b/c dog fighting is still very rampant here (I wanna say i read a statistic that its one of the popular locations for it) so I've gotten to a point where as a reflex i get nervous when random guys approach like that b/c of the negative history i've had over it. Turns out this guy was totally cool and really nice but when he approached Greta flipped out. Started growling, barking and would not let him near me (he was a good 15 feet away and that didn't seem like it was enough for her). Once i realized he was a good guy I explained to him the breed and how their protective instincts (he totally understood) and after a few minutes of chatting she cooled down and I went to shake his hand, she became very friendly and even let him pet her. Nowadays I try to be more aware of what kind of "energy" i'm giving off when people come up to us and she's been just great. She still is very watchful of everything and anything and has no qualms in letting someone know to watch out if they try to sneak up on us or something. I'm not sure whether she would go as far as biting and i won't be pushing that anytime soon, right now she's still a baby and its all about building up her confidence but i have no doubt, she will protect me and my daughter at all costs.