Why do so many riders perch even at a slow lope sometimes?

Perching is so common because it feels safe, and that's the cruel irony of it. When a rider is uncertain or unbalanced, the instinct is to grip and lean forward — it feels like you're more in control, more secure, more ready to react. In reality you've just put yourself in the worst possible position for all three of those things, but the body doesn't know that. It's doing what feels protective in the moment, and breaking that habit means overriding a pretty deep-wired physical response. A big part of it is also that perching allows the rider to use their legs as a brace. When you come up out of the saddle and stand slightly in the stirrups, you can grip with your knees and thighs and create a feeling of security that way. It's false security — grip actually stiffens your hip joints and prevents you from following the horse's motion — but it feels solid enough that riders return to it under pressure without realizing they're doing it. Fear plays a role too. A rider who has been bucked off or spooked on a fast horse often develops a forward-lean habit as a subconscious defense mechanism. The logic, buried beneath conscious thought, is that if the horse spooks I'll grab his neck and hang on. That's understandable, but the position makes a spook more dangerous, not less. Sitting deep and following the motion is what keeps you with a horse through unexpected moves. Perching is what gets you launched. The cure is confidence and miles — specifically slow miles in a correct position until sitting deep becomes the reflex instead of the leaning. A knowledgeable instructor who can give immediate feedback accelerates this process significantly.