Sibling Jealousy: Causes and Strategies for Parents

Why does sibling jealousy happen? Adapting to a new baby, managing jealous behaviors, and evidence-based ways to foster healthy relationships between siblings.

Quick answer: Sibling jealousy is a natural response to loss, of attention, exclusive time, and 'only child' status, not a behavior problem, and it's common in a new baby's first year. It often shows up as regressive behavior, clinginess, or occasional aggression toward the baby. Help by giving the older child at least 10-15 minutes of dedicated one-on-one time daily, involving them in caregiving tasks, and acknowledging jealous feelings without punishing them.
Reviewed by: Whispie Editorial Team Evidence-Based Parenting Research

Published:

This article is for general information and is not a substitute for professional medical advice. Always consult your pediatrician or doctor about your child.

Sources: WHO, CDC, AAP and NHS guidance. Recommendations differ between countries — for local advice see the NHS or CDC.

See how we research and review →

Why Does Sibling Jealousy Happen?

The birth of a new sibling is a genuine loss experience for the older child: loss of parental attention, exclusive time, and their "only" status in the family. Psychologists compare this to an adult experiencing a partner's infidelity — an exaggeration perhaps, but it captures how intense the emotional experience is for the child. Jealousy is not a pathological feeling; it's a natural adjustment response that needs to be processed.

Research shows that approximately 80% of older children display regressive behaviors (bedwetting, requesting pacifiers, baby talk) or aggression during the new sibling's first year. These behaviors are the child's way of saying "I'm still here, love me too."

Free tool: Developmental Milestone Checklist by Age (CDC): 2 Months to 5 Years

Signs of Sibling Jealousy

Preparing Before the Birth

The most effective intervention begins before the sibling arrives. Research shows preparation interventions significantly reduce adjustment difficulties.

The First Weeks After Birth

Responding to Jealous Behaviors

Punishing regressive behaviors worsens the situation; it's necessary to see the underlying need.

Building the Sibling Bond Long-Term

Research shows that strong sibling bonds improve the child's social skills, emotional intelligence, and stress tolerance. This bond doesn't form on its own; it requires active parental facilitation. Good family communication — where each child feels heard — is one of the most powerful tools for nurturing that bond.

Whispie Quest

A week-by-week programme of screen-free activities pitched at your child’s level: a fresh plan every morning, made from what is already in the house.

Also from Whispie

Weekly parenting tips, no spam

Evidence-based guidance for your child's stage — straight to your inbox.