There's no doubt that feral pigs pose a danger to humans, but how about your average, domesticated pig?
You won't find many articles on domestic pigs that went on rampages, but there has been a recent case where a wild 600 pound pig injured a woman while feeding livestock on her property in England. A pig is just like any other animal, and will lash out if feeling cornered or mistreated. In general, domestic pigs are not dangerous, but they can bite, since they are natural foragers. And they can be especially dangerous if you try to hog-tie them or round them up in any. But domestic pigs are just like any other domestic animal that can be trained.
Aggression in domestic pigs depends on a variety of factors. The breed of the pig will determine whether or not it is aggressive, or if the parent displayed anti-social behavior before. The genetics of the pig do tend to outline its behavior in the same way as dogs.
Pig behavior depends on their age.
Young piglets who grow up without social interaction may end up being antisocial and unfriendly towards people and other pigs. Piglets that were fed by bottles, or weaned before six weeks of age, may display aggressive tendencies in a year. But the good news is that you'll have plenty of time to curb and train your young piglet, so these behaviors do not become more ingrained as it gets older. You can do these things yourself. It is better to have an aggressive piglet than a 500 pound hog with a chip on its shoulder. And when it comes to mothers, sows will be more far aggressive to protect its piglets. But the mother can also be to blame, since she may not have taught her piglets valuable social and interaction skills.
Aggression can also develop in older hogs that have status within the herd. Pigs that have an alpha male complex may also be a bit more brazen than most hogs, but this can be broken with proper house training.
And when it comes to training, you must see through the eyes of a pig. Even though pigs can be trained like dogs, keeping them friendly requires different methods than canines.
Setting strict housing standards will keep the pig from becoming a problem hog. And spoiling your pet pig could lead to behavioral problems. This is not the problem in every case, since pigs have different personalities, but it is possible if the hog is aware that it can get away with just about anything without facing consequences.
But if rules are too strict, the pigs can also lash out. Like dogs, pigs within abusive or neglected homes have a higher chance of acting out with aggression. The pig will also learn to be aggressive if its human owner exhibits the same behavior. Pigs that sit too often with nothing to do will become strained with boredom, resulting in personality issues. A pet pig must have toys to keep it entertained, along with being around other pigs or human beings to foster happiness.
If you're pig is displaying some aggressive mannerisms such as biting, you can do the following.
If you have a domestic pig, try not to startle it in any way, but if it is becoming aggressive, clap loud or say "no" in a loud voice to startle the pig. This will make them forget what they were doing. And you can take on position of head hog by taking your hand and applying pressure to the pig's shoulder. Hogs do this in general to assert their dominance. As long as the pig knows you're the head honcho, behavioral issues should not be a problem.