Two self-organizing groups under mutual informational constraint produce teleodynamic signatures (F0 decreasing over time = self- organizing under constraint) that a single isolated group cannot produce. COUPLED condition gives each agent last-3-turns context from the other group. ISOLATED is the bandwidth-matched control. Alt H0: informational coupling at this level has no measurable effect on structural differentiation; F0 trajectories match. Ladder position 1/5: simulated coupling (engine enforces summary injection; agents do not "feel" real resource depletion). Cheapest substrate test. Null here motivates escalation to compute-gift (2/5).