I think folks may have always had a special one they claimed as a pet out of the laying flock, but it just wasn't something they advertised to everyone. I remember banty hens sitting on our shoulders as kids out of my grandfathers flocks. Now that chickens are showing up in urban backyards, they are living closer to their human keepers, who see more in them than the average farmer might, who keeps them at arms' length and goes out to grab one on the spur of the moment for that night's supper. JMHO. So, they've become more popular as pets than they used to be. They're easier to leave overnight or for a couple of days than a dog would be. I don't plan to have another dog after my elderly girl passes on because I do find lots of pet qualities in chickens, as well as the usual eggs & fertilizer.