ABSTRACT. Giftedness, the potential for exceptional achievement, is characterized by high intelligence and creativity. Gifted people exhibit a complex of cognitive, perceptual, emotional, motivational and social traits. Extending neurophysiological hypotheses about the general intelligence (g) factor, a construct is proposed to explain these traits: neural propagation depth. The hypothesis is that in more intelligent brains, activation propagates farther, reaching less directly associated concepts. This facilitates problem-solving, reasoning, divergent thinking and the discovery of connections. It also explains rapid learning, perceptual and emotional sensitivity, and vivid imagination. Flow motivation is defined as the universal desire to balance skills and challenges. Gifted people, being more cognitively skilled, will seek out more difficult challenges. This explains their ambition, curiosity and perfectionism. Balance is difficult to achieve in interaction with non-gifted peers, though, explaining the gifted's autonomy, non-conformism and feeling of alienation. Together with the difficulty to find fitting challenges this constitutes a major obstacle to realizing the gifted's potential. The appendix sketches a simulation using word association networks to test the propagation depth model by answering IQ-test-like questions.