Every male dog I've ever owned has been super friendly with strangers and every female dog I've ever owned has been highly suspicious of strangers, regardless of breed. Anyone else notice this pattern with dogs they've owned? In fact the sire of one of our German Shepherds was so indiscriminately friendly that someone stole him. Her mother, however, was so aggressive with strangers that she had to be locked away when strangers came to the breeder's house.
