Add Yahoo as a preferred source to see more of our stories on Google. American inventor John Larson, right, demonstrates the operation of a polygraph at Northwestern University in Evanston, Illinois, ...

There's no foolproof way to prove that your sister actually stole your sunglasses, but polygraphs can sometimes do a pretty good job. Here's how to throw together a DIY polygraph machine with nothing ...

Here’s a video of Marston using a polygraph-like machine and claiming to identify the varying emotions of blonde, brunette and redheaded women. His conclusion was that redheads like to gamble, ...