Actually, nothing is further from the truth.  Terrier breeds were bred to attack vermin, Flock Guards were bred to attack predators that threatened the flocks and herds, Hounds were bred to attack game, and many many other breeds including Spitz breeds and Sporting will also attack quarry and other animals.  Untrained dogs will often kill other animals becaue dogs are still predators by nature, and still have a prey drive.  The 'Pit' breeds are very much terrier, if you wish to ban them, then ban all dogs, for all breeds are capable of killing animals smaller than they.

 

No animal has locking jaws.  Spotted hyenas, have the strongest jaws of any land mammal, and they can not lock their jaws.  Their strength comes from their cheek muscles, they have a wide head and beautiful bone structure to support such power.  Jaw power varies from dog to dog, a dog that has not excerised it's jaws will be weaker than one that has, but this still does not make a dog Dangerous. 

In bite work, it is well known that you want a dog to take an arm as far back into the mouth as possible and hold, this gives even pressure over a large area and causes less damage than a frontal mouth bite from even a much weaker dog that will slip during a struggle, tearing skin and muscle tissue, and result in multiple re-bites.

Lock Jaw is a condition that is more common is pigs and humans than in dogs, and is caused by a tetanus infection, hence tetanus shots, and can result in death if not treated.  It is not caused by some mechanism. 

 

Not proven.  As I stated above, Spotted Hyenas have the strongest jaws of any living mammal, and Tassie Devils are right behind them with being able to chew through thick steel cables in less than a night.  Spotteds are believed to have 12,000 PSI, capable of crushing Elephant bones, but the problem is within measuring bites...

Bites can vary not because of breed, but because of training, jaw exercise, how much pressure the dog want's to bite with, and even the day.  Also, the equipment is not always right.

However a recent study:

Three breeds of dog were tested - a GSD, Rottweiler, and a Pit Bull. All three dogs had about 320 psi. The Rottie had the most, and the GSD the least.

Interestingly enough, humans have about 120 psi.

 

Not true.  If they were then we'd have millions and millions of dog bites from them.  We don't  There is possibly more than 16-18 MILLION "pit type" dogs in the US today.  They are popular, and any time a breed become's popular, there will be more bites noticed by that breed....because there's more of them!

The American Temperament Test Society has tested many different breeds, and 'Pit Bull' type dogs rank one of the top passing rates for their high numbers!  One tester, who tested pits for many years stated that only one 'Pit' had shown signs of human aggression.

The APBT's(American Pit Bull Terrier) nature was one that was shaped by the rule of 'Man Eaters Die'.  When they were fought, this rule kept the breed culled and turned them into one of the most stable tempermented dogs with humans ever to be seen.  But popularity does horrible things, and often these days, the 'Man Eaters Die' rule is often broken.  Not to mention people who want a fighting dog that will be 'tough' and 'attack'.  If laws were passed to make the owners responsible for attacks that make no sense and could and should have been prevented, then maybe people will start thinking differently.

 

Satistics are never 100%.  There are bites from other breeds, even ones from the same dog, that are never reported because the dog is a.small, b.a family breed, or c.it's nothing serious(yet).

Also, Satistics get messed up by the fact that many people don't know one breed from the next, some people even group any bitting dog to mean 'pit bull'.  Mixed breeds, no matter if they are 'pit bull' looking, should be with the mixed breeds, pure bredss should be in their breeds, and unknowns should be called unknown.  People like to sound like experts, and even the media is known to call a breed something other than what it is.  So the data on breeds goes out the window.  Besides, you can fix more problems by looking at the circumstance the bite came from rather than the breed.