A framework describing the two poles of bad body language: the shy guy, who is afraid to take up space, and the cocky guy, who overcompensates and takes up too much / goes over-the-top. Despite looking like opposites, both are diagnosed as coming from the same place — insecurity.
The corrective target isn't the opposite extreme (a shy guy shouldn't push toward cocky, and vice versa) but the calm, relaxed middle: how you already act around close friends or around someone who already likes you. This is the same 'good body language is what you already do in low-stakes contexts' idea underlying Anti-Seductive Traits (The Self-Awareness Gap), and ties to Body Language Follows Belief (Indirect Coaching) since the behavioral symptom (shy or cocky) is read as evidence of the underlying belief, not a separate problem to drill independently.
Chase Hughes gives this same insecurity-rooted pattern a named model — the Composure Pendulum. Posturing (over-trying, performative confidence — the cocky-guy end) sits on one side; collapse (making yourself smaller to appease others — the shy-guy end) sits on the other. Both are rooted in insecurity; composure is the secure middle ground, not a compromise between the two extremes but a distinct third state.
Hughes illustrates the pendulum with Andy Griffith and Barney Fife from The Andy Griffith Show: Barney oscillates between posturing and collapse throughout the series, while Andy stays centered in composure — see The Andy Griffith Method (Random-Episode Leadership Lesson) for the training exercise Hughes built around the show. He also cites Marcus Aurelius's description of his general Maximus (from The Emperor's Handbook, 121 AD) as one of the clearest descriptions of composed authority: "Maximus set an example of self-mastery, steadiness of purpose, and good cheer that no circumstance, not even illness, could extinguish."
This maps to the confidence signal in Hughes's The Five Authority Trip Wires.