It has even been shown that owners who have a prejudice against a certain race or social class can relay such feelings to their dog. Dogs, like humans, are prone to making mistakes. It may misinterpret an action or momentarily not recognise a person and spring to the attack. This has been evidenced on many occasions when dogs have suddenly and without warning struck out at their owners. The ancestry of the dog, which is believed to go back to the wolves of the wild, is another possible explanation for the aggressive streak which is evident in dogs.
Some breeds also appear to be more aggressive than others.
One dog which has a reputation as a natural born killer is the pit bull. According to Randall Lockwood, a Humane Society expert, These dogs can be canine crocodiles. They have a dark and bloody history. The facts bear this out. 72 percent of all deaths by dogs in the United States are attributed to pit bulls.