Tibetan Mastiff (detailed introduction)

　　 Dog biting problems are common. Many people judge whether a dog will bite by first observing the dog’s breed, but now there are many cases of Golden Retrievers biting people. Why is this? Is it a genetic mutation or has the environment changed the dog?
　　 In fact, a dog’s “breed” is only one of many factors that affect aggression. According to a recent study published in the journal Animal Behaviour Science, the biggest influence on a dog’s aggressiveness is its owner—that is, the owner’s training method, acquisition location, gender, and age are most closely related to the dog’s aggressiveness.
　　 Additionally, the same dog may be aggressive in one place but not in another. For example, it may bark wildly on the street but be gentle in its own backyard. “The causes of dog aggression are very complex, related to ‘condition dependence’ and ‘historical dependence between humans and dogs,’” said Stephen Zawistowski, scientific advisor to the American Society for the Prevention of Cruelty to Animals (ASPCA). “You cannot predict a dog’s aggression based solely on breed.”
　　 This study on dog aggression has several points worth noting:
　　 1. Dogs owned by people under 25 years old show almost twice the aggression of those owned by people over 40.
　　 2. The aggression of neutered male dogs is twice that of neutered female dogs. However, there is no significant difference in aggression between neutered and unneutered males.
　　 3. Dogs that did not undergo training during puppyhood are 1.5 times more aggressive to strangers than trained dogs.
　　 4. Using punishment and negative reinforcement in training dogs tends to lead to aggression.
　　 5. Dogs obtained from shelters or similar sources are more aggressive than those purchased directly from breeders.
　　 Stephen Zawistowski emphasizes the importance of puppy socialization and notes that if an older dog suddenly becomes aggressive, it may be due to illness.
　　 Mary Burch, director of the Canine Good Citizen program at the American Kennel Club, said, “If you worry about being attacked by an unfamiliar dog, pay attention to its body language. Early aggressive behaviors include direct staring, stiff posture, raised hair, ears or lips pulled back, showing teeth, growling, barking, etc. If it is only barking, it should not be defined as aggression.” She criticized a British study for defining barking as aggression, “because barking can have many meanings.” Dogs barking wildly may be warning the owner or sending messages. “In my view, this is an overly broad definition of aggression.”