Julia Twomey-Davie: Enneagram Types & Jungian Archetypes, 1994

Julia Twomey-Davie presents her dissertation linking the Wagner Enneagram Inventory to Carol Pearson's 12 Heroic Archetypes—the first empirical study to test both systems together. Testing 185 subjects with five psychological instruments, she found that anxiety predictably triggers disintegration pathways: anxious Ones, for example, shifted toward Four traits and away from Seven.