Biodiversity and cultural diversity are morally valued.

Humanity is facing rapid declines in both biodiversity and cultural diversity. As effective conservation policies often require strong public support, it is critical to understand whether individuals view diversity loss through a moral lens and whether they value diversity for its own sake, independent from instrumental or individual-centric concerns. Across two studies (N = 796), we found that individuals assigned moral value to both biodiversity and cultural diversity. Individuals assigned greater moral value to animals, plants and - to a lesser extent - languages when diversity was threatened, compared to when it was not threatened, despite an equal number of entities at risk, and they were willing to sacrifice a large number of these entities to prevent a loss in diversity. Additionally, we found (N = 12,000) that a general concern for diversity underlies concern for both biodiversity and cultural diversity. These findings suggest that emphasizing the inherent value of diversity may be effective for increasing public support for conservation of diversity.