I don't know how I missed this for so long.

I have believed for many years that chickens make what we might call emotional bonds. I have also read a little on Oxytocin and spoken to other chicken keepers who don't fall about laughing, or try to tell me I'm anthropomorphising, who recount some of the more extraordinary relationships they have observed in the chickens they care for.
There's a lot we don't understand about chickens which is very odd given we've been abusing them in just about every way imaginable for hundreds of years.
A good read I thought on an interesting topic.
By the way, I've found grooming is the fastest way to a roosters heart.