Knee Jerk Reactions from Paul Archer on Vimeo. Paul takes a different look at objection handling relating this to knee jerk reactions. As a kid, I was fascinated when doctors would carefully tap a patient’s knee with a small hammer and the patient’s leg would involuntary kick upwards. That’s where the phrase “knee jerk reaction” comes from. For years after first seeing this on TV, I tried in vain to make my knee do the same. Join Paul now for in this 5 minute video and audio clip.