The knee-jerk effect was documented in the 19th century [0]. I was certainly aware of it when I was young (1970s) although I can't remember whether it was expli

The knee-jerk effect was documented in the 19th century [0]. I was certainly aware of it when I was young (1970s) although I can't remember whether it was explicitly taught at school, either the effect or the underlying cause. [0] https://en.m.wikipedia.org/wiki/Patellar_reflex#History https://en.m.wikipedia.org/wiki/Patellar_reflex#History