Nick Sidwell OTR/L

The Moro reflex—often called the “startle reflex”—is a primitive reflex present at birth. It’s an automatic, involuntary response to sudden changes in sensory input, such as loud noises, bright lights, or unexpected movement. When triggered, a baby will:

Quickly extend their arms and legs outward
Open their hands
Then bring their arms back toward the body (often appearing like a “hug” motion)
Frequently cry afterward

This reflex is thought to be a survival mechanism, helping infants respond to perceived threats and signal for caregiver support. The Moro reflex typically integrates (goes away) by 4–6 months of age as the nervous system matures and voluntary motor control improves.

If the Moro reflex does not integrate or disappear, it is considered a retained primitive reflex. The reflex continues to get in the way of how the nervous system responds to stress and sensory input. This can ultimately affect children—and even adults—in subtle but significant ways. A retained Moro reflex is often linked to difficulties with regulation, sensory processing, and emotional control. Common signs may include:

Sensory & Regulation

Overreacting to loud noises or sudden movement
Difficulty filtering sensory input (easily overwhelmed)
High levels of anxiety or “fight-or-flight” responses

Emotional & Behavioral

Emotional reactivity or mood swings
Difficulty calming down once upset
Low frustration tolerance

Attention & Learning

Poor focus or distractibility
Difficulty with transitions
Challenges with impulse control

Physical & Postural

Poor balance or coordination
Motion sensitivity
Fatigue from constant “alert” state

From a nervous system perspective, a retained Moro reflex can keep the body in a chronic “Flight-or Fight” response, impacting participation in daily activities, connection and social engagement with others, and natural development patterns. Sometimes birth trauma or significant medical complications get in the way of the integration, sometimes limited tummy time or movement opportunities in infancy, chronic stress or environmental instability, or even just differences in sensory processing or development

The good news is that the nervous system is adaptable. With targeted, repetitive movement and regulation strategies, the Moro reflex can often be integrated later in life. Occupational therapy (especially with a sensory integration or neurodevelopmental approach) is often helpful, but there are also things families can do at home. Here are some common exercises to do at home that focus on rhythmic movement, controlled input, and building tolerance to sensory experiences.

1- Starfish Exercise (Moro Integration Movement)

This is one of the most commonly recommended exercises.

How to do it:

Start curled up in a ball (arms crossed, knees tucked)
Slowly extend arms and legs outward like a starfish while inhaling
Bring arms and legs back in while exhaling

Reps: 5–10 repetitions, 1–2 times daily

2- Deep Pressure Activities

Examples:

Bear hugs
Weighted blankets (used appropriately and supervised)
Pushing against a wall (“wall push-ups”)

3- Slow Rocking or Rhythmic Movement

Examples:

Rocking in a rocking chair
Gentle swinging
Slow rolling on a therapy ball

4- Breathing + Movement Pairing

Teach simple breathing:

Inhale through the nose while opening arms
Exhale through the mouth while closing arms

Why it helps:
Combines motor control with regulation, supporting parasympathetic activation.

When To Seek Professional Support

Consider an evaluation by an occupational therapist if: The child shows significant sensory sensitivity or anxiety, emotional regulation is interfering with daily life, there are ongoing challenges with attention, coordination, or behavior. An OT can assess primitive reflexes within the broader context of sensory processing, motor skills, and functional participation.

A retained Moro reflex isn’t just “something they will grow out of”—it can negatively shape how a person experiences the world. The key is recognizing the signs and supporting the nervous system through intentional movement, regulation, and consistency. With the right strategies, meaningful improvements in regulation, attention, and emotional resilience are absolutely possible.

What Is The Moro Reflex?