What are the valid criticisms of natural horsemanship?

Natural horsemanship has attracted genuine and substantive criticisms that go beyond simple resistance to change, and engaging with them honestly is important for practitioners who want to think clearly about the tradition they are working in. The most serious scientific criticism is that some natural horsemanship frameworks — particularly the horse psychology models used by Pat Parelli, Clinton Anderson, and others — misrepresent how horses actually think and behave according to equine behavioral science. The left-brain versus right-brain horse categorization used in the Parelli framework does not reflect the actual neuroscience of horse cognition, and the dominance hierarchy model that underpins Clinton Anderson's respect-first approach significantly oversimplifies the complex, context-dependent social relationships that horses actually maintain. The claim that natural horsemanship methods are more natural than alternatives is also contested: horses in the wild do not engage in round pen exercises or groundwork games, and the appeal to nature does not in itself validate specific training approaches. The marketing dimension of natural horsemanship has attracted criticism for prioritizing the sale of equipment, programs, and branded systems over the development of genuine horsemanship skill — a concern that applies most directly to the heavily commercialized programs of Parelli and Anderson and less to the more austere traditions of Dorrance and Brannaman. The risk of anthropomorphism — projecting human emotions and motivations onto horses in ways that misinterpret their behavior — is present in some natural horsemanship frameworks that emphasize horses' desire for partnership, feelings of trust, and emotional responses in terms that exceed what the behavioral evidence supports. And the excessive time that some natural horsemanship programs spend on groundwork before riding — potentially months or years of groundwork before the horse is considered ready for under-saddle work — has been criticized as unnecessary delay that the horse's welfare and the rider's practical goals do not justify.