Horses - although trained and kept by humans, are they essentially still wild animals?

Question

Are they really domesticated or not?

Answer 1

Yes, they are domesticated and have been over thousands of years.  A domesticated animal is an animal who has been selectively bred over generations.  Humans select animals with physical and behavioral traits that the human finds beneficial and then lets those animals breed.  The offspring have a high chance of also having those wanted traits.  This process keeps going.  Even today horses are selectively bred to be even better at doing what we want.  Take race horses for example.  Fast horses, ones who have won many races, are desirable as breeders.

Compare domestic horses to wild ones like Zebra.  Zebra are aggressive and not as strong for bearing riders.  Often the "zebras" seen being ridden in movies and some circuses are just painted horses as the real zebra is not likely to be cooperative.

Interestingly, domesticated animals also tend to have smaller brains than their wild relatives since they don't have to deal with figuring out how to survive.  This is true of dogs and cats VS wolves and wildcats.  I'm not sure about horses though.