How it works
Like charges repel, so individual hairs push apart. Dry air allows charge to remain longer, while moisture helps it leak away.
What people often miss
Static is not created from nothing. Electrons move between materials, and grounding or added humidity can reduce the imbalance.
Why this question comes up
Winter heating and synthetic fabrics make the effect especially common.
Key points
- Hair becomes staticky when contact and separation transfer electrons among hair, clothing, brushes, or other materials, leaving strands with similar electric charges.
- Like charges repel, so individual hairs push apart. Dry air allows charge to remain longer, while moisture helps it leak away.
- Static is not created from nothing. Electrons move between materials, and grounding or added humidity can reduce the imbalance.
Bottom line
Hair becomes staticky when contact and separation transfer electrons among hair, clothing, brushes, or other materials, leaving strands with similar electric charges.
Source and verification
This Answer was checked against Library of Congress Everyday Mysteries. Follow the source for the full official explanation and any later updates.