Is Hoarding in Our Genes? What a Landmark Twin Study Reveals

June 20, 2026 - 19:11

A new landmark study on twins suggests that genetics play a much larger role in hoarding behavior than previously thought, particularly for women. Researchers found that genes account for roughly 50 percent of the risk for developing hoarding difficulties. The shared family environment, meaning the home and upbringing that twins experience together, contributed very little to the outcome.

The study, which analyzed data from thousands of twin pairs, points to a significant genetic link. For women, the heritability of hoarding traits was calculated at about 50 percent. This means that half of the variation in hoarding symptoms among women can be attributed to genetic factors. The other half was explained by individual life experiences, such as personal trauma, unique friendships, or specific events that one twin experienced but the other did not.

These findings challenge older views that hoarding is primarily a learned behavior or a result of a cluttered upbringing. While a messy home environment might play a small role, the study suggests that for many women, the tendency to hoard is heavily influenced by their DNA. The results also help explain why hoarding often runs in families, even when siblings are raised in very different conditions later in life. Researchers hope this genetic insight will lead to better treatments and reduce the stigma around a condition that is often misunderstood as simple laziness or poor housekeeping.