It's anecdotal, but... We lived outside Philly, rescued a "pit bull mix" from SPCA who was a stray found in the streets of Chester, PA, had scaring on her hind legs that they assumed was from being used as a "bait dog" (related to fighting). They assumed she was 1 year old when we adopted her. So emaciated that she had lost most of her hair, and didn't make ANY sounds for 3 months! She was the sweetest dog I have ever known. Amazingly patient with kids, would "pull punches" when playing with tiny children... Just a big cuddle princess. We lived in a twin (duplex) and shared a driveway; attached neighbor and a neighbor that had windows facing ours, 12 ft away. We were robbed one day while she was home, and the windows were open. Our neighbor (across driveway) saw the guys cross his back yard (very odd due to fences and 10 ft retaining wall that completely enclosed our yards... no reason anyone would be back there) and got on the phone with police as he went out and walked into our back yard. He looked through the back window to hear the 2 guys run down the stairs and see them run out the front door. He said he never heard a bark, even with both of our house windows open! Honestly, with the reputation pitbulls have, I'd rather she let us be robbed than worry about her with kids and mailmen... I'd choose to have our "ferocious" girl again every single time I had the option. We eventually had a DNA test done just before she passed away (almost 14), and found that she was 100% Stafford Shire Terrier (frequently called/interchanged with American Pitbull Terrier, although some organizations designate them as different breeds)