Can anyone give a demonstrable example of mental illness in other mammals? Is there any evidence of say schizophrenia, bipolarity, or the currently popular ADHD, etc?
I think the important factor to keep in mind here is the fact that most animals that have been closely studied have been in captivity. This is bound to skew any behavioral observations similar to studying human prisoners. Studying mammals in their natural habitat would probably be the only way to get some answers to this.
If the answer is no, then I guess the real question here is – are human mental illnesses a result of us humans being “civilized”? Perhaps someone like Jane Goodall would have something to say. Jane, are you out there?
It would be extremely difficult to diagnose them, because diagnosis of most human mental illnesses require interviewing the patient (heck, it’s hard enough to diagnose mental illnesses even in humans). That said, any pet owner can tell you annecdotes about crazy pets, and it’s probable that some of them do have similar underlying conditions to the recognized human mental illnesses.
Animal behaviorists have documented that pets can definitely get a variety of neurosis. For example, a pet dog that is forced to live with a high level of stress and anxiety may start circling behaviors, staring at walls for hours and other behaviors. Fear aggression is also triggered by being forced to live with stress. Here’s a link: http://www.petmd.com/dog/conditions/behavioral/c_dg_compulsive_disorders
For non-pet species, I think the movie Blackfish did a pretty good job of describing how the whale Tilikum was captured as a young “teenager”, isolated from others of his species for many years in a small tank, forced to learn to perform and was punished when he “misbehaved”. They didn’t state it outright but everything they described to me sounded like psychosis. Relating the whale’s experience to a human, it was like if a 12-year old boy witnessed his family being murdered, was kidnapped and held in a small jail cell for years, forced to perform in a circus by people who didn’t speak the same language as him, punished whenever he acted out, and finally held in solitary confinement for years. Who wouldn’t be crazy after that?
Oh, and don’t forget the documented experiments where baby monkeys were isolated from living mothers: Pit of despair - Wikipedia
Long ago a group of squirrels used to visit our patio to look for acorns blown of the nearby oak tree. There were usually 3 or 4 normal squirrels going about their business of digging through leaves and branches looking for something good to eat, sometimes engaging in squirrel play, sitting up to look for other friends or enemies, the usual squirrel behavior. And then there was Psycho Squirrel. He would dart back and forth from spot to spot, constantly freezing looking around side to side before jumping to another spot. He wouldn’t mix in with the other squirrels on the patio, from off to the side he’d leap onto the patio, grab something then leap off. They could climb the stucco walls and Psycho Squirrel would do that all the time to get around the other squirrels on the ground. His behavior was definitely weird, clearly set apart from the others. He was a little scrawny, but otherwise didn’t look sickly, and he was there for a year that we were in that apartment so if he had a physical illness it wasn’t that bad. So I have no way to know why is behavior was so strange, but if you had seen you would have thought that he was not right in the head.
Some forms of insanity are caused by physiological aberrations in the wiring of the brain or nervous system, and other mammals would be subject to analogous defects or abnormalities. But other forms of insanity arise when the conscious and rational human fails to compensate in socially acceptable ways to environmental events, and thus being diagnosed as insane. These would be less likely, and possibly absent, in non-social and non-intellectualizing mammals.
As long as “insanity” is held to be a broad construct that encompasses both of the above, you’d be inclined to assume that nom-human mammals would be subject to one of the causations, and not the other.
Some social species of mammals have been observed to recognize a “rogue” among them. If psychiatry existed within that species, the rogues would no doubt be called insane.
This looks promising but, as you know, until we can rule out all other possible explanations … These squirrels could not be considered as being in captivity or unduly influenced by a human presence so maybe you have something here. In the end it might be impossible to know one way or the other. The only possible route I see is by looking at our closest relatives.
If mental diseases have a genetic component, and we share 90-whatever percent of our DNA with chimps, why not ?
Of course homosexuality was until fairly recently classed as a madness, and animals get up to a lot that, plus some other stuff. Otters will rape a baby seal until it dies and then rape the corpse. What’s sane about that ?
Anecdotally at least, there are dogs that are apparently born crazy. Not just quirky, crazy. I’ve heard of many, I know of several second hand and a couple first hand, owned by dog trainers I know and respect, so merely bad-behaving or environmentally damaged dogs are eliminated. These sicko dogs seemed relatively normal until something triggered them. Sometimes the trigger was not discerned by the humans, sometimes it was. Once triggered the dog would attack whatever was closest with lethal intent, whether that was their best buddy or a bystander or their owner. After the episode was over the dog would return to being a normal dog.
One dog the breeder suspected of being deprived of oxygen during the birth process (she was present at it).
Obviously these dogs tend to not live out their natural lifespans. I imagine psychotic animals in the wild would also mostly not live to reproduce.
I have heard that parrots will commonly go insane if left in isolated conditions. Elephants have been known to snap after decades of good behavior. I also believe farm raised pigs tend to get loony.
So, assuming the absence of a physiological cause, a mammal could only exhibit anomalous behavior if it were evolutionarily adapted to being a social species. Other mammals that were not social could only exhibit a form of insanity that has its origin in biology.
Then it would follow that insanity in this sense is a matter of definition. Conduct deemed unacceptable or anti-social could be regarded as insane.
I think one problem is that most forms of severe (thus observable in the non-verbal) mental illness are not good things to have if you want to survive in the wild.
It could be that mental illness isn’t “caused” by human captivity, so much as ‘mentally ill animals surviving for any length of time to be observed’ is “caused” by human care.