Humans are uniquely skilled at deliberately inducing altered states of mind, a practice evident since early civilization, but its role in the evolution of the human mind is debated. While psychoactive substances are common today, it is unclear if pre-human ancestors used them. With great apes retired from medical research, researchers analyzed YouTube videos of apes spinning ropes during solitary play. Apes spun at speeds comparable to human practices like Sufi whirling, and the number of revolutions predicted behavioral signs of dizziness. Spinning thus provides a self-sufficient method for altering body-mind responsiveness in hominids, suggesting a shared proclivity for such experiences between humans and great apes and offering a new avenue for studying altered states in human evolution.
Rhythmic movement—such as dancing, chanting, and breathwork—is consistently linked to altered states of consciousness across human cultures, though systematic research is scarce. The authors propose four neurobiological mechanisms: modulation of autonomic activity through breathing changes, psychological amplification via expectation and fear, vestibular perturbations that distort proprioception and multisensory integration, and neural entrainment affecting brain oscillations and connectivity. They also review comparative evidence that rhythmic movement induces altered proprioception, arousal, and social attunement in nonhuman great apes, and suggest that rhythmic stereotypies (e.g., rocking, pacing) may be analogues of rhythm-based ASC inductors. These findings point to deep evolutionary roots for rhythm-induced state changes.