[Solved] How, according to Eaton, should the causal relationship between pornography and harm be understood, and how should it not be understood? Fixed-Action Pattern: A sequence of innate behaviors that is both unchangeable and, once initiated, carried to completion. Learning: The process of acquiring new, or modifying existing, knowledge, behaviors, skills, values, or preferences through experience or education. Nervous System: Organ system of humans that includes the brain, spinal cord, sense organs (eyes, ears, etc.), and associated nerves. Receives, integrates, and stores sensory input; coordinates activity of other organ systems. Endocrine System: Organ system involved in the coordination of body activities; uses hormones as chemical signals secreted into the bloodstream.