Sensory Processing Sensitivity: A Review in the Light of the Evolution of Biological Responsivity

By Aron, E. N., Aron, A., & Jagiellowicz, J. (2012), Personality and Social Psychology Review, 16(3), 262-282. doi: 10.1177/1088868311434213 

Key Takeaways

What Is Sensory Processing Sensitivity (SPS) — And Why It Matters

Sensory Processing Sensitivity (SPS) is a scientifically studied trait that helps explain why some people — and even animals — experience the world more intensely. These individuals are often described as Highly Sensitive Persons (HSPs).

A recent scientific review highlights that high sensitivity is not a weakness, but rather a natural and evolved trait that can bring both challenges and strengths. Understanding SPS can help parents, teachers, and therapists better support sensitive children and adults.

Sensitivity Is an Evolutionary Trait — Not a Disorder

Researchers found that sensitivity is present across many animal species, not just humans. It’s believed to have evolved as a survival trait — sensitive individuals are more alert to subtle changes and may sense danger or opportunity sooner.

That means: sensitivity has a purpose. It’s part of how nature ensures balance within a group.

The 4 Core Traits of Highly Sensitive People (HSPs)

The review paper identifies four key features of SPS:

1. Depth of Processing
   Sensitive people think deeply and reflect more. They may take longer to make decisions because they consider every detail.

2. Emotional Reactivity & Empathy
   Emotions hit harder — both good and bad. HSPs often cry easily, feel deeply moved, and have strong compassion for others.

3. Overstimulation
   Too much noise, chaos, or sensory input can quickly become overwhelming. HSPs need more downtime to recover.

4. Sensitivity to Subtleties
   They notice tiny details — changes in tone, facial expressions, lighting, or textures that others might miss.

Together, these traits explain why highly sensitive children often react strongly, need quiet moments, and are deeply affected by their surroundings.

From Baby to Adult: How Sensitivity Develops

The review also explores how sensitivity shows up early in life. Some babies are more reactive, alert, or easily startled. These traits often grow into what we now understand as SPS or high sensitivity in adults.

The researchers also developed the well-known HSP Scale, a questionnaire used around the world to help identify and support highly sensitive individuals.

Why This Research Matters for Parents, Educators, and Therapists

If you're raising or working with a highly sensitive child, this research can guide you. It shows that:

• Sensitive children thrive in warm, supportive environments

• They are more impacted by both positive and negative parenting

• With the right support, they often grow into empathetic, creative, and socially skilled adults

This fits with the idea of differential susceptibility — sensitive children are more shaped by their environment, for better or worse.

*This blog post is based on publicly available scientific research. It was written to make complex insights about Sensory Processing Sensitivity (SPS) easier to understand for parents, caregivers, and professionals. We paraphrase and simplify the content with respect for the original study by Aron et al. (2012), published in Personality and Social Psychology Review.