Narcissistic siblings can be just as harmful as narcissistic parents, and their behaviour often leaves emotional wounds that continue into adulthood. Growing up with a narcissistic sibling means living with constant tension, confusion, and subtle manipulation that many people don’t recognise as abuse until much later. One of the most common behaviours is relentless competition. A narcissistic sibling sees you as a rival rather than family. Your achievements threaten them, so instead of celebrati