By now, we have all read about the recent savage attack on a woman by a pet chimpanzee. The woman's face was literally ripped off her skull, causing her to lose both eyes, her nose, and most of her jaw. In addition, she has severe damage to her hands and arms. If this incident sounds familiar, it is because a similar attack occurred in 2005. That attack also resulted in a person losing most of his face, and in that case also his genitals and most of his fingers.

In both cases, the chimps had been raised by humans, and in both cases the owners had no real explanation for why the attacks occurred. Various theories were put forth, but none of them, in the end, made any real sense. The owners of Moe claimed that the chimp that attacked them was jealous of Moe because they had brought him a cake. The owner of Travis, the chimp involved in the most recent attack, at first claimed that she had given him Xanax shortly before, but then quickly retracted that statement and speculated that he had attacked her friend because the friend had a new hairstyle.

Even if these excuses were true (and honestly, they are just guesses), how does that change the facts or the conclusions that we can draw from them? There are essentially two versions of the story. In one, the animal attacks without reason. In the other, the animal attacks in response to an extraordinarily small event or change. Either way, what you are left with is that people are keeping pets that are capable of ripping a human's face off in a matter of seconds, with either no or very little provocation.

So why do people do this? There is lots of misleading and confusing science out there about chimps and their relationship to humans. Many chimp advocates and owners quote research saying that chimps share 95% of human genetics. (The figure used to be higher, 98%, but recent complete sequencing of the chimp genome shows that the percentage is lower than previously thought.) But still, people think, 95% is a lot - practically the same! But you have to realize that *all* life on earth shares genetic material, because we all came from the same primordial soup. As an example, we also share about 90% of our genetics with pigs, but no one says that pigs are "just like humans". To go a little further, we share about 50% of our genetics with insects, and only slightly less with plants. When you look at these figures in comparison, you can see that we are dealing with very small differences being responsible for very large changes.

Another frequent statement to justify treating chimps as human 'children' is a study, widely misunderstood, that shows that chimps have the cognitive abilities of a three-year-old human child. This comparison is based on testing that indicates that chimps are capable of learning various tasks that are equivalent to what a human toddler could learn. However, it is only in certain areas and tasks that this is true, such as learning rote physical tasks, and the basics of language acquisition, such as naming objects. They are also very good at understanding and solving physical puzzles and understand the idea of substituting one object for another (for instance, they can understand the idea of collecting tokens that can be exchanged for food). But there are other, equally significant things, that they cannot learn. They cannot learn the concept of delayed gratification, for instance, nor can they really learn self-control. In various studies, for example, chimps have been offered two bowls of food, one with a lot of food, one with very little. Chimps will immediately grab for the bigger bowl, even if the result of that is that the bigger bowl is taken away and they are left with the smaller bowl. A three-year-old child will figure out immediately that the way to get the bigger reward is to reach for the smaller one. But chimps cannot prevent themselves from grabbing the bigger bowl, no matter how many times the experiment is repeated. Eventually they get frustrated and start throwing the bowl at the researcher, or storming away and attacking other elements in their environment, including other chimps or inanimate objects.

This is one way in which chimps are very much like toddler humans. When faced with frustration, fear, anger, boredom, or sometimes for no discernable reason at all, they have temper tantrums. But there is a big, big difference between a small human child striking out at those around him or her, and a 200 pound chimp with the relative strength of five adult male humans striking out. When chimps have temper tantrums, people end up horribly maimed or dead.

Which is why chimps belong with other chimps, not with humans. In the wild, when chimps react violently to something, the focus of their ire is other chimps - animals of equal strength. But when chimps are raised by humans, they do not have the normal chimp outlets for their aggression - they don't have other chimps to rough-house with as youngsters, and they don't have other adult chimps to challenge and argue/fight with. All that repressed behavior has to come out somewhere and eventually it will. Animal trainers who work with chimps will only work with young animals, usually under the age of ten, because when they get older they become too unpredictable and too physically powerful to be safe. And then, like Moe and Travis, they usually come to a bad end. They are sold to science labs, or to roadside zoos, and in the end most of them end up being euthanized.

Simply put, private ownership of these animals should be illegal. No ifs, no ands, no buts. It's cruel to the animals, it's dangerous to people - there is nothing positive to be gained, and far too much to be lost.

For a balanced look at the attack in 2005, check out the video below: