Why do you think it is important that a polygraph measures responses that are largely involuntary instead of voluntary?

Polygraphs measure involuntary responses, like heart rate and galvanic skin response, because these physiological reactions are less susceptible to manipulation or control by the individual. This involuntary nature can provide more reliable indicators of truthfulness or deception, as they reflect genuine emotional and psychological states. By focusing on these automatic responses, polygraphs aim to capture authentic reactions that may reveal underlying truths that a person might consciously attempt to conceal.