How do string harmonics produce a high flutelike sound?

String harmonics produce a high, flutelike sound because they isolate specific overtones by dividing the vibrating string into equal parts.1

When a string vibrates as a whole, it produces a fundamental pitch; however, when a player touches the string lightly at a specific nodal point—a location where the string would naturally divide into segments—they dampen the fundamental frequency and the lower overtones. This action forces the string to vibrate in these smaller, equal sections, which produces higher-frequency harmonics that are integral multiples of the fundamental frequency.12

Because these higher harmonics are emphasized while the fundamental tone is suppressed, the resulting sound loses the complex, rich timbre of the full string and takes on a pure, thin, and flutelike quality. These can be produced on open strings as natural harmonics or on stopped strings as artificial harmonics.1234