You need to feel SECURE. From Amir Levine, MD, coauthor of the multimillion-copy bestseller Attached: What’s the secret to finding success, happiness, and love? Amir Levine, MD, coauthor of the multimillion-copy bestseller Attached, returns with a groundbreaking new insight from the latest research: your attachment style isn’t fixed. It is relationship-specific: you can be secure with one person and anxious or avoidant with another.