My Arab at 5 spooked at the mounting block, door whatever for me and for his trainers. But when my sister got on, nothing. He'd try a spook and she'd ignore it and continue on. And he wouldnt try it again.
It really irritated the trainers, lol. She was not a better rider than the trainers, she .. I don't know, she didn't care? She just continued on.
She is a better handler on the ground too, calm, non nonsense, consistent and non emotional.
At least in this case, it really was the rider.
He's just a baby. I wouldn't drill anything. Don't focus on one "spot". He anticipates that it will be made into a big deal.
Keep it light and breezy. Short rides. Ride out on trails with his nose in the butt of a trusty older horse. Lots of hand walking and trailering out to new places, even if all you do is hand walk or lunge him.
Believe it or not but the more places you drag him off to the better he will be at home. It will become much less exciting once he's seen the real world.
This is an old Quarter Horse trick. They drag young horses all over the place. They tag along to every show, even if they just stand tied to the trailer or walk around on a rope.
Wow, you have my horse. Right to the bolting in hand, spooking into you when nervous and doing the "plant-snort, spin&bolt" combo.
Honestly, that sounds exactly like my horse when i got him when he was 4. He was great on his "good" days, almost a little lazy to ride, a real gem. On his bad days, he was almost unmanageable. Shows were a disaster his baby green year. He'd go into the ring, "see" something, then all thought and reason left him. He'd refuse to go forward, would spin, spook, suck back, etc.
For the spooking into me, I'd goose him in the ribs with my elbow or the pointy end of my dandy brush. My trainer always said to "match his intensity". So if he's about to bowl me over in a blind spook, I'm digging it in as hard as I can (or, letting him slam into it). If he's being just mildly rude, the correction is quieter. I used that mentality throughout his life. If he's nice, I'm nice. If he's not, I'm not.
Time and exposure will help. Get him out to see everything you can. We started bringing my horse to little shows to just "hang out" in his baby green year on the weekends he wasn't actually showing. We'd toss him in his stall with a bunch of hay until he settled and then longe him, letting him spook on the longe and getting some beans out before anyone got on him.
On weekends he was showing, we'd bring him a day in advance to hang out, longe, get walked around the grounds (with a chain over his nose), and hacked in all the arenas we could.
Learning how to longe properly was a big thing, too. Keeping the whip at his shoulder so he couldn't drop the shoulder and dip in/spook. Making him trot to the rhythm I dictated, not the one he wanted to do - i.e, crazy fast.
Picking battles is a huge thing. My horse has always hated weird noises. One show grounds has a texas gate that cars rumble over right by the warm-up area. He'd lose his mind - turn into a shaking, bolting, sweaty mess. I picked that battle: we just never warmed up by it. We'd go to a different ring where there might be something spooky that he could mentally "get over".
Weirdly enough, treats helped. All the big decor in the middle of the show grounds would sometimes set him off so in schooling, my trainer would walk us over to it and then give him his fav treats for being "brave". Ridiculous but it really helped.
Also, I wore big spurs. I never needed them when he was being good, but the second I felt him start to "look" and suck back, those spurs were in his ribs before he could actually drop the contact and suck back. I'd sit deep in the saddle (usually sitting trot), and put him into a leg-yield. Bend+using brain+turning away from what was spooky made him go past it. Did that a few times and he'd trot past fine. When he wouldn't, I'd make it harder for him: shoulder-in at the canter. The second he'd suck back, my inside spur would be digging into him HARD.
When he was green and before he could shoulder-in, we'd do shoulder-fore. Before we could do that, sometimes we'd follow a buddy into the "spooky corner".
Honestly this is after years of trial and error. He was a very difficult horse to have but he made me a better rider and took me from baby greens to 4'3s before he was injured. It's tough but experience, exposure, and finding out what works will help your horse through this.
I noticed an improvement with my guy when he was 6-7, but even when he was 12 I'd have people telling me "oh, warmbloods just take longer to mature. How old is he? 6? wait til he's 8..."
Sidenote: I also had him on thiamine (which helped), an herbal supplement called calmer, and I just now - him at 18 years of age - put him on magnesium. The magnesium has been a BIG help. Not that he pulls these tricks (much) anymore, but it seems to make him calmer and less reactive. I said to my mom, "why didn't I learn about this before?"
I got my Arab just shy of his third birthday. He was intact and a spooky, brainless fruit loop until he was almost 5. He got gelded at 4 (not behavioral, just life changed and plans to show/breed him changed too). He was incredibly easy to break out, never cared about wearing whatever tack I wanted to put on him. Never cared about having someone on his back. At 3, his attention span under saddle was good for around 20 minutes. Much past 15 minutes and he started just losing his marbles. It wasn't that he was trying to be bad or disobedient, it really seemed like he just couldn't process anything past that time. He'd go all ADD on me and if I tried to make him think too hard the boogymen started popping up everywhere. He'd just get stupidly spooky.
At 4 (real 4, not like January 1, 4), he was much more capable of focusing on work for a solid 30-45 minutes at a time. Again though, much past that and we started into spooky moron land again.
Taking him to new places always resulted in spooky moron brain.
What helped? Ignoring the spooking and just making him deal. There was a lot of riding out the colt stupids. There was a lot of working near the scary thing. You're going to lose your mind over that puddle? Okay we'll work only within 5 feet of it then. Taking my jacket off is scary? Okay, I'll put it on and take it off a thousand times. Then I'll flap it in your face and you get to deal with it.
Arabs see gremlins everywhere. Especially young Arabs. I knew this going in. So we worked on it. We hauled all over creation. We did all kinds of things that have absolutely nothing to do with what I actually want to focus on. Fun gaming show in town this weekend? Sounds good to me! Cutting clinic next Saturday? Count us in! I promise, the baby buffalo won't eat you! Just ANYTHING that got him out in the world seeing new things. Each new thing that didn't kill him, gave him that much more trust in me.
Now he's almost 8 and not much truly spooks him anymore. He still has the Arab startle thing, but these days its limited to either a sideways step or the freeze/duck in place rather than the ZOMGRUNFORTHEHILLS!!! reaction he used to have.
Also, in his mind, treats solve everything. Something is scary? Cookies are involved? He's totally in.
I do the you get your treat in the spooky place treatment with my OTTB mare. It seems to help her... but she is generally pretty confident.
I also have a warmblood mare who is big and pushy and a little spooky. She also picks spooky parts of the arena. One of the things we did a lot of is halt, move the shoulders away from the rail and back again. When she wants to spook I halt and move her shoulders to the spooky thing... of course she is 19, not three... I did the same thing when she was three, but it is, of course, much more effective now than it was then. It also helps to sneak up on the scary thing... start working farther away and get closer through out the ride without making a huge issue of it... and I have to remember to never look at the scary thing, just ride like there is absolutely nothing going on outside the ring. She is now pretty fun to ride most of the time and absolutely reliable in as much as I do not lunge her ever... no matter how bad the weather, or how long she's had off.
I vote for more time and less emotion. My young not-OTTB is pretty insecure but like your young guy, he is not hot...at all. But he spent the better part of ages 2-4 in a stall, healing a tendon laceration (the reason he is not OTT and why I have him). So he did not come with the advantage of being exposed to a gazillion things going on in track life.
Luckily, he is not herd-bound. But he will fixate on corners in the arena and sometimes over-react to simple things like a cat sitting in the arena doorway.
I just deal with the behavior and try to not get upset. He is also very sensitive and will pick up if I am nervous. And I have found that as he gets older, he is gaining more confidence. Just seems to be taking much longer than my other young horses.
Do you have Lyme in your area. When my guy had Lyme this summer, he became 10 times worse. There was one day that I tried to work through the reluctance to go past one door and it evolved into a total spooking, spinning session. 12 weeks of doxy and he is much, much better.
Good luck and try not to get too frustrated.