This is based solely on my own experience. I own a 12yo OTTB - he has not raced since he was at least 5, and counting from his original owner/breeder, I am his 7th owner.
When I got him almost 4 years ago, he was polite, but not "warm and fuzzy". I could not touch his ears - period, unless I was putting on a bridle or halter. I found out, through trial and error, that I can clip his bridle path, but not his ears. I can, however, play with his ears however I want. That took time. Did not like his face rubbed, chin or neck scritched. Sometimes, would like butt scratches (talk about feeling low down - here you can scratch my butt...)
Personality wise, he is essentially lazy, will do what asked, but has a stubborn streak when asked to do something he doesn't particularly feel like doing. He is has, for lack of a better term, an oral fixation. His blanket has to stay in a box, or he will play with it in his stall until it is dead. Learned that the hard way. All the other kids have their blankets folded across the back wall of their stalls when not in use. He has been known to filch his neighbor's to play with.
He has warmed up to me on the ground, a lot. When I go to get him from the pasture (sans treats - don't want to get mugged), he either comes to meet me or stands and waits for me. I normally tack up in his stall, without him being tied. We have a "deal", as long as I am currying, brushing, etc., he can root around for leftovers. When I get ready to pick feet, he stands straight and in the center of his stall. That is not something I deliberately taught him, just worked out that way.
Under saddle, we do ok. I have an OMG what could happen sort of brain and I have to really keep it under control. He has never maliciously dumped me. The times I have come off of him, he has stayed right there, even the time the arena gate was wide open.
After I had had him for a while, I started dismounting in various parts of the ring and "asking" him to walk with me - not being led. He did and now does it very well. This came in handy in the in hand obstacle class we did one time - got a blue ribbon - LOL. He walks when I walk, he stops when I stop. Today, we walked all the way back to the barn from the arena - reins over his head - me not actively leading. He didn't stop once and try to graze.
A few weeks ago, since I can only ride on the weekends and he is a TB, my trainer taught me to lunge him in side reins. The side reins are to get him to use his back and get off his forehand. We lung without the side reins attached for most of the session, don't want to kill him. The first time we used the side reins, my trainer with me, he did fine to the left, but his stubborn streak showed up to the right. We got that worked out.
The first time I did it alone, same thing. Left good, right, stubborn, but we worked it out. Today, right good, left stubborn. I have noticed tyhat he keeps his inside ear on me at all times. Once we are through lunging, I ride.
First time I rode after the lunge session, he was so much more relaxed and listening to me instead of wondering what the others were doing in the pasture. Same thing today. Well, there was the one spook - but even his occasional spooks are now different. They used to be to the side (hate those) - now they (2) seem to be down - sucks me into the tack!
Ok, - the point of this novel is this. Not only is my horse easier to ride, but he is much more "affectionate" on the ground. He suddenly likes his head rubbed. As I said before, we walked all the way to the barn without him being led and I was the leader all the way.
So, have the lunging sessions created a closer bond between us or does he see me more firmly as his leader? Either way is good for me.