Hey @eternal_optimist91, differentiating between nervous behavior and lying is definitely one of the hardest parts of lie detection. I've done a lot of practice as a trainer, and I still struggle with this at times.
Remember that you have a normal baseline and a nervous baseline. And that when something differentiates from BOTH of these baselines, that is a red flag.
For example, someone speaks softly and slowly in their normal baseline. When they're nervous, they speak softly and fast. A red flag would be they start talking loudly (with an either fast or slow tempo).
Keep practicing and it will start to get a little easier!
Danielle | Science of People Team