I heard about both inventions on TV and decided to look it up. Here is what is said about the matter at http://goodcomics.comicbookresources.com/2005/10/06/comic-book-urban-legends-revealed-19/
COMIC URBAN LEGEND: Wonder Woman creator William Moulton Marston invented the polygraph test!
It has long been a funny sort of dramatic irony that William Moulton Marston, creator of Wonder Woman and her golden lariat, which forces people to tell the truth, was also the inventor of the polygraph test, which (purportedly) detects whether people are lying.
However, this is not the case.
Marston WAS, however, an early innovator in the field of lie detection, and his contributions to the polygraph test should not be overlooked, for Martson DID, in fact, invent the first lie detector of any sorts, in 1917. In 1921, Martson published his doctoral thesis for Harvard University. The title was “Systolic blood pressure symptoms of deception and constituent mental states.” That was Marston’s innovation - the idea that, by testing a subject’s systolic blood pressure, one would be able to determine whether the subject was lying.
The polygraph test, however, uses three OTHER methods, not just blood pressure. It is only when using the four methods combined that the results of the polygraph test are achieved. The other three tests are for heart rate, respiration and skin conductivity.
Still, one out of four is very impressive!