Cochins have relatively long soft feathers.
Go to a show and ask to try and pet one of each of these breed against the lay of the feathers and you will be able to tell the difference. I don't know the physical reason for the differences, but they must be structurally different. Either the protein compostion or how the proteins are arranged must be different in these feather types. There must be a genetic cause because the traits are breed characteristics. This is a private posting area.