Sibling Rivalry: When Childhood Stories Linger Into Adulthood

Sibling rivalry - most of us have experienced it in some form. The squabbles over toys, the competition for parental attention, the silent comparisons, the need to be seen, heard, or simply “better than.” While rivalry between siblings is a natural part of growing up, what’s often overlooked is how deeply those early experiences can shape our sense of self, and how, if unaddressed, they can follow us long into adulthood.

Why Sibling Rivalry Happens

As children, our need for love, validation, and safety is foundational. When multiple children are raised in the same household, even in the most loving environments, there’s often an unspoken competition for these emotional resources.

But this isn’t just psychological, there’s a physiological basis for it too.

The Physiology of Sibling Rivalry

During early childhood, our brains are still developing, particularly the limbic system, which governs emotional responses, and the prefrontal cortex, responsible for logic, reasoning, and empathy (which doesn’t fully mature until our mid-20s). This means children interpret the world emotionally first, and logically much later.

At the same time, the nervous system is learning what feels safe and unsafe. When a sibling receives more attention, praise, or physical closeness, a child’s amygdala (the brain’s threat detector) may interpret it as a sign of danger:

“If I’m not chosen, I might not survive.”

This may sound dramatic, but it’s actually hardwired into us. From an evolutionary standpoint, a child instinctively knows that connection to caregivers equals survival. Anything that threatens that bond, even a sibling getting more hugs, can feel like a life threatening event to a developing nervous system.

This sets off a stress response:

• Increased cortisol (stress hormone)

• Heightened vigilance (comparing, competing, and people pleasing)

• Emotional reactivity (tantrums, withdrawal, and jealousy)

Without support, undertanding and emotional regulation, these responses become internalised as beliefs:

• “I have to be the best to be loved.”

• “There’s not enough to go around.”

• “Love is conditional.”

• “I don’t matter.”

And what starts as a survival response in childhood becomes the blueprint for how we relate to ourselves and others in adulthood.

The Lingering Impact in Adulthood

Many adults carry the invisible weight of sibling rivalry into their careers, relationships, and self-image. Without realising it, they may operate from the same emotional patterns they developed in childhood.

Some common internal narratives that stem from unresolved sibling dynamics include:

• “I’m not enough.”

  A belief that no matter what you achieve, it will never measure up.

• “I’m unworthy.”

  Feeling undeserving of love, success, or happiness, as if these things were only “available” to others.

• “There’s no space for me.”

  A deep sense of invisibility or the need to shrink yourself so others can shine.

These beliefs don’t arise in a vacuum. They are often formed in subtle moments, a parent praising one child more often, a sibling excelling where you struggled, or simply the unspoken dynamics of a household trying to balance it all.

But Here’s the Good News: It Can Be Undone

These patterns are not your fault, they were formed at a time when you were doing your best to understand the world and your place in it. And while they may have lingered for years, even decades, they are not permanent.

With awareness, compassion, and intentional healing, these childhood imprints can be reworked. Here’s how:

1. Name the Story

   Start by identifying the narratives you may have inherited. Whose voice says you’re not enough? Is it really yours, or did it begin somewhere else?

2. Validate Your Inner Child

   That younger version of you needed to feel seen, safe, and valued. Offering compassion to that child, not judgment, is the first step to healing.

3. Work with a Therapist

   Therapy can help you explore these sibling dynamics in a safe and supportive environment, making sense of them with adult awareness while freeing the emotional energy still tied to the past.

4. Rebuild Self-Worth from the Inside Out

   Worthiness isn’t something you earn by outperforming others, it’s something you reclaim by coming home to yourself.

Moving Forward

Sibling rivalry might have felt like a rite of passage in childhood, but its emotional residue doesn’t have to define your adult life. If you find yourself stuck in patterns of comparison, perfectionism, or feeling like happiness is reserved for everyone but you, you are not alone. And more importantly, you are not broken.

These stories can be rewritten. Not by pretending the past didn’t happen, but by facing it with honesty, grace, and a deep commitment to your healing.

You are enough. You are worthy. And everything you long for is available to you, not because you’ve earned it, but because it’s your birthright.

Need support in working through childhood dynamics and reclaiming your sense of self?

I’d love to support you on that journey.

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And begin the work of coming home to yourself.