nrhareiner you make excellent points. I am sorry this is long. There are certain personality points that can be buffed down with training.
Do not confuse Personality with Temperment. Temperment is inherited personality is what WE as humans make it.
The issue then maybe that people I see breeding have not done the sufficient amount of training on. Lets not lie, it takes a lot of work to raise a well mannered horse from foal-hood to adulthood. A lot of people perhaps don't put in the work that is necessary and so the dam has a lot of flaws that if left to their own devices can be passed on to the offspring.
Yes and no. If you are talking the biological dam then this could be true. However you do not see a lot of breeder who rase the dam and the foal both from birth. Also this could come down to the fact that what they are doing wrong with the dam they are with the foal. If you cange humans you might see something very different. Also I go back to ETs. Full siblings one an ET and one not. You will see that these foals/horses have more incommon then not. Has more to do with breeding them anything.
As to people taking one thing and breeding only for that it does happen. It happens in all elements of riding, be it dressage, halter or reining.
I suppose it depends on what the one things is and how you define it.
Ex. Tabasco cat. A horse known for his bad temperament that was a success in the breeding shed because he won a few good races as a 3 year old. Keep in mind that horse put the owner's son in a wheelchair. If that horse was not a success on the track he would have never made it as a stallion. I saw someone who wanted to breed their one eyed, thin thoroughbred to a neighbors arabian stallion. The stallion has to be sedated for routine grooming. In both cases, these are horses that should not have been bred IMHO. The good traits did not outweigh the bad traits.
Again are these things man made or not? Now where the offspring when bred to different type of mares. I have a mare here on the property whos sire was know for not having the best temperment. He was a hard horse. He was also a great show horse. I have been around many of his get including the one I have. All have been great. Good temperment easy to ride and train. My mare has her sires stop and ability. Love that mare. Would not hesitate to have anouther one if he was still living.
Yes, you are right though, well bred and well trained horses can do many different things. I don't know that many people spend the time to make sure their horse is diverse enough before breeding.
Why? I have no interest in doing anything but reining and reined cow horse. So my horses are bred to do those events trained to do those 2 events and yes they could do many other things and at times I do take them and do other things with them but I do not care if I do or not. It is more for fun or something to do then anything. Most people are like that. They have their disciplines they like and do and could care less about any other event.
Some people breed very talented and well balanced horses but a lot of people take horses that are not well balanced (physically, training wise and emotionally) and breed them. I know this but I guess I put more emphasis on the well trained element of that than on the well bred. There is also how you define well bred. I know a lot of folks who consider well bred to be line bred, I prefer outcrosses.
I want to start with well bred. You can change the training or add to it. You can not change the horses breeding it is what it is. To me well bred is proven sire and dam for what the horse is bred to do. Ex if I want a horse for reining I want proven sire and dam in reining. Better yet I want every horse on that horses pedigree to be proven.
Its all in what you are looking for. You are going to breed what you are looking for. If you are looking for a diverse horse with a good personality and a willing spirit you are going to breed for that. If you are looking for a dishy face you are going to breed for that. You can look at english bulldogs for the extreme this goes to. They want big blocky dogs with smooshed faces and wrinkles. What they have as a breed are big, blocky dogs with smooshed face, and wrinkles that also have skin problems, need to be AI'd, don't free whelp, can't be in the sun and often need corrective surgery for their narrow noses. These are the dogs that win in the conformation show ring. The dogs being breed in the agility or herding arena are not going to correspond. The difference between conformation (bench dogs) and the dog at your house (field dog). You can see this division between show and work horses in Morgans and Arabians. In breeding, its about what you are looking for and find desirable and different people like different things. I think a hyper-focus on one physical trait can be bad for any breed of any species. (look at the family tree of British royalty for a case of human line breeding gone wrong).
Same with my dogs. When I went out and got my Golden. I wanted a certain type of dog. I got what I wanted and she has 3 AKC titles before she was a year old. She hunts well is a great retriever does well in water is a great theropy dog loves to go to nursing homes. Past that I could care less what she can do. She does what I want in her. Same with my mares. I could care less if they do anything but rein as long as they do that very well.