Good intro to the early days of the lie detector as it was invented and used in USA. It's largely a historical overview of how it came about and became a giant hit in USA. The supreme court made it illegal for cops to torture people into confessions and they needed other methods to force and persuade people. Similarly Hollywood and marketing campaigns wanted to use the lie detector to market their products and see what people enjoy or react to. And there were people ready to sell it to any bidder. We follow 3 men who each invented their own lie detector and then 1 guy who took over. The documentary doesn't really focus on smaller names or cases. If these 4 were not involved the documentary just overlooks the cases. The psychologist who invented Wonder Woman is a sleazy salesman while another guy who made a much better lie detector is fighting these salesmen who are just trying to use the lie detector as a 100% correct machine and right away use it to solve murders and sell products without even caring if it's valid or not.
Honestly it's a great intro. It's 1 hour too short but that's it basically. Of biases I did notice that every time they bring up race they show a bunch of Black people in photos and then have a Black narrator telling us how cops can be mean etc. This is just silly as I'm sure there are experts of any race ready to talk about racial issues and there is no need to force points this way. But American Experience is typically way more progressive so this is not a huge bias. The documentary never really gets into if the lie detector works or not or how it may have failed in some cases. It's presented as a proper and valid machine and the misuse is just said to be caused by ignorant people controlling the polygraph. Which is just weird. There have been notorious cases of communist spies tricking the lie detector yet the documentary presents zero such cases and the pundits never once mention a single case where the lie detector failed in catching a lie. Does it work? We don't know. We just see how it was used and then finally banned from company use by Reagan and now mainly used for fun or by cops and agents.