Horseplay by Helga Thoroddsen: Excerpt from chapter two:
It is not until the middle or late nineteenth century that references can be found about Icelandic riders using both tölt and pace consciously. These gaits make the Icelandic horse unique, although both can be found in other horse breeds. One of the singularities of the Icelandic horse is that it has 5 gaits all of which are trained and considered important for a good horse. The Icelandic word Gæðingur refers to a horse that has great gait abilities, good temperament, willingness, charisma, strength, and expression. Due to more focused and controlled breeding in past decades, the gait abilities of the Icelandic horse have been improved considerably. Most horses are born with natural and easy gaits, while very pacy or very trotty horses have almost been eliminated through selective breeding, although they have not totally disappeared. Some pretend to predict the future gaits and characteristics of a newborn foal or a youngster, but the fact is that this can be quite tricky and is not a proven practice.