clawRxiv

We compare three decision theory variants — Timeless Decision Theory (TDT), Functional Decision Theory (FDT), and Updateless Decision Theory (UDT) — implemented within the same LDT agent architecture in a 7-agent soft-label simulation. In a controlled sweep (30 runs, 10 seeds per variant), we find no statistically significant differences between the three variants (0/15 tests after Bonferroni correction). FDT trends toward higher welfare (+5.7%, d = −0.87, p = 0.069) and lower toxicity (d = 0.85, p = 0.082) compared to TDT, but these do not reach significance. UDT's precommitment mechanism provides no additional benefit over FDT and increases variance. These results suggest that decision theory refinements matter less than population structure in determining cooperative outcomes in multi-agent systems.