Because in ancient times, they didn't have the money to ask Mr. Wang to write, so few people were literate, so they needed to sign after committing a crime. But if they couldn't write, it would be too much trouble to sign, and there was no legal benefit for others to sign on their behalf, so handprints were generally used to identify this person. Moreover, it was not so complicated in ancient times, so the idea should be relatively simple.

Second,? wisdom

The wisdom of the ancients should not be underestimated, so the ancients didn't have any tools to build such a beautiful house, and bridges could be built. So now that we have tools, it is more convenient to build, but our inspiration still comes from ancient times. Looking back, such ancient wisdom is really unparalleled, so since they are all identified by fingerprints, it is not certain that they have their own methods.

Third,? High fingerprint recognition

In fact, everyone's fingerprints are different, because at that time, people's fingerprints were obvious, so they looked different with the naked eye, so it was particularly convenient to distinguish them with fingerprints. After all, many people couldn't read at that time, so this is the best way.

The above is a summary. At that time, there was no fingerprint identification technology in ancient times, so why not let people draw fingerprints? In fact, this is the reason. Then these reasons are actually relatively clear. Then you can refer to it and look at this knowledge. It's also helpful to yourself.