
The Psychology of Sibling Rivalry: Normal vs. Toxic
Understanding the Roots of Sibling Dynamics If you have more than one child, or if you grew up with a brother or sister, you know the sound. It is the sudden screech of “That’s mine!” followed by a thud, tears, and the inevitable “Mom! Dad! Come here!” As Dr. Peyman Tashkandi, I have sat with countless families who feel like their home has turned into a battlefield. Parents often look at me with exhaustion in their eyes, wondering where they went wrong. But I want to start by telling you something important: conflict is not always a sign of a broken family. In fact, the sibling relationship is often the longest-standing relationship a person will have in their life. It outlasts the relationship with parents, and it usually predates spouses and children. Because of this, the psychology behind how siblings interact is incredibly complex. It is a training ground for


















