The Green Line Test is a theory that claims to determine who is in charge in a relationship based on body language in photos. The test involves drawing a vertical green line through each persons back in a photo of a couple. According to the theory, whoever leans into the other person is the less dominant partner, and whoever stands up straight is really in charge. However, there is no scientific basis for the Green Line Test, and the entire idea is based on a faulty premise. The test was invented by a Twitter user who has a history of discussing pick-up techniques and incel-backed theories like the "red pill". While the Green Line Test has gained popularity on social media, it is not a reliable or accurate way to assess power dynamics in relationships.