Class Notes (835,107)
United States (324,041)
PSY 344 (34)
Davenport (34)
Lecture 25

PSY 344 Lecture 25: Detecting Truth and Lies (polygraphs)

3 Pages
Unlock Document

PSY - Psychology
PSY 344

Psych 344 4/28/17 Psych and the Law Detecting truth and lies (polygraphs.) A. Detecting truth and lie - Polygraphs- one of most common methods for determine lies - Polygraphs detect lies by detecting reparation, blood pressure, skin response, heart rate, movement...physiological response - Not detecting if telling lie, detecting if physiological changes in body. - What about someone with high blood pressure? Someone who is just a nervous/ anxious individual? - Not a lot of standardization of administering polygraph. This is one of the big problems. B. Administering the polygraph- - First thing done is saying, “if you lie, this machine will know.” - This is a standard instruction. - Used to make person nervous. - Control question test- requires the administer give two types of test - First type- relative questions about the crime - Second type- “control type” about common misdeeds. Ex: “have you ever stolen anything prior to the age of 21?” - Considered control questions in which most people would answer yes to. - Assumes that innocent people will lie to common misdeed questions. They will get nervous, and get a baseline to physiological spike - Looking for what lie looks like. - Point is- innocent person nervous about misdeed questions and not nervous about relevant questions. - Guilty person would be nervous about relevant questions, and not nervous about misdeed questions. - Directed lie test- variation on control question test. - But subject told to lie about control questions. - Based on the assumption that the guilty person thinks the examiner will know what it looks like when they lie. - Guilty knowledge test- goal is not to have person lie to anything - Instead administer is trying to detect what knowledge the person has - Administer asks question and gives multiple choice answers - Watches device and watches device for spikes during multiple choice questions. - Ex: Knife was found by a. bed b. by back door c. by hedge - Done slowly so that administer can mark physiological response. Goal is to see spike when person hears right answer. - Don’t even have to answer question. - Assumes that innocent person hasn’t heard any information about the case. Has to be info that hasn’t been released
More Less

Related notes for PSY 344

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.