In ancient China, what was the primary use of fingerprints before their current identification purposes?

The primary use of fingerprints in ancient China was to authenticate a document. This practice highlights the early recognition of unique physical characteristics, which were employed to validate the identity of the person associated with a document. By using fingerprints as a form of signature, it provided a reliable method for ensuring that the documents weren't falsified and that the individual’s identity was adequately represented. This historical use laid the groundwork for the eventual evolution of fingerprints into a standardized method of personal identification and played an important role in legal and bureaucratic processes within the ancient Chinese civilization.