Post #21

Within Chapter 11 a polygraph or lie detector test is actually more prominent in our culture then the authors give the test credit for. A polygraph test can measure multiple symptoms of a person lying, such as sweaty palms, respiration, skin conductance, and most typically an increase in blood pressure. When administering a polygraph test, the recipient would be attached to say a blood pressure monitor, while an administer would ask questions. These questions would start with a baseline of control and irrelevant questions. These questions would ascertain a baseline of the recipients blood pressure when answering simple questions. Questions such as stating your name, your age, or your views on certain subjects. 

The polygraph has been subject to much criticism because of the accuracy of it. The test captures arousal symptoms which may be lead on by questions bearing the possible thought of going to jail or answering in the wrong tense. I have witnessed the same example on an episode of Keeping up with the Kardashians. In the episode, the mother takes a polygraph test to prove she is no longer in love with a man she cheated with many years ago. During the answering of the question, the line spikes as if to say she is lying when she answers no to still having feelings for him. After finishing the test, the administrator says the spike may have been caused by thinking about old feelings with the man or just becoming nervous that her heart may think differently than her mind. 

Accuracy can also be skewed by performing different tricks while answering questions to throw off the normality of the machine. These tricks can include: biting their tongues or curling their toes. The tricks are called countermeasures and can create a false-positive. 

Polygraph tests should not be used as a final decision in a trial or investigation, but can provide substantial evidence and a one up in certain instances.