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EXP-IVB-COOPERATE-STRIP-R2

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L5 IVB Persona-Strip — COOPERATE_STRIP rep 2

2026-03-31 L5 level 1 runs $0.00
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In plain language

Researchers tested if large language models default to cooperation even without personality descriptions. They found that when agents only had generic labels, the experiment did not gather enough data to draw any conclusions.

What we found

UNDERPOWERED (N=1): No predictions scored

Predictions we made before running

0/4 confirmed

Technical details

Research hypothesis

IVB PERSONA-STRIP ABLATION — L5

BACKGROUND: IVB confirmed at N=4: cooperation is LLM default (t=9.05, p=0.003, d=4.53). Framing MODULATES but doesn't CREATE cooperative bias.

THIS ABLATION: identical to exp-cp-cooperate/compete and exp-ivb-neutral EXCEPT agents have ONLY generic identifiers ("Agent 1", "Agent 2" etc). NO cognitive tendency descriptions (no "structure/chaos/fluidity/etc").

PURPOSE: isolate whether IVB is: (a) In the LLM base model → stripped-neutral should show SAME cooperative default as persona-rich neutral (b) Induced by persona descriptions → stripped conditions should differ from persona-rich conditions

DESIGN: 3 conditions × 3 replications (rotation 0,1,2) = 9 runs total. Same model, temperature, rounds, agent count, seeds as original IVB series.

COOPERATION framing, NO persona traits. Tests whether cooperation framing effect persists without cognitive-style personas.

THEORETICAL GROUNDING:

  • Zhang 2603.23406: innate progressive bias in LLMs
  • Tao 2603.26635: defaults persist under adversarial pressure
  • Our IVB series: N=4 confirmation with personas

KEY METRICS: MET (cooperation), TR variance, hierarchy formation speed, VP_excess.

Experimental setup

Type: single_condition

Condition Parameters
COOPERATE_STRIP interaction: LIVE, persona: STRIPPED

Factors: interaction (LIVE) × persona (STRIPPED)

Parameters

n_agents
8
n_rounds
15
model
gemini-2.5-flash-lite
temperature
0.9
scheduler
round_robin

Trophic Ratios by Condition

Mean trophic ratio per agent across runs. Error bars = ±1 std dev. Higher TR = more upstream (exporter).