Dealing with other people and dealing with horses are two completely different matters. Sure, people respond to the threat of being grounded, but here again is where predators and prey animals think differently. The idea of using a spur as an escalation of aid would be correct, but the application IMO is not the best way to deal with a lazy horse. It's force....and force doesn't just mean beating a horse. Force comes in many, many different forms....from things that are deemed acceptable to abuse, and everything in between. We shouldn't have to get stronger with a horse, we need to use pshychology and understand what these types of horses need....making their body go with the use of a spur does not engage the mind, and with these kinds of horses it's a MUST that we engage their mind. I like the idea that the rider will know they are ready for a spur when they don't think they even need a spur, that their horse is so responsive and light that they might not even see a need for a spur (even for higher level maneuvers).