Personality Requires Struggle: Three Regimes of the Baldwin Effect in Neuroevolved Chess Agents
arXiv:2604.03565v1 Announce Type: new Abstract: Can lifetime learning expand behavioral diversity over evolutionary time, rather than collapsing it? Prior theory predicts that plasticity reduces variance by buffering organisms against environmental noise. We test this in a competitive domain: chess agents with eight NEAT-evolved neural modules, Hebbian within-game plasticity, and a desirability-domain signal chain with imagination. Across 10~seeds per Hebbian condition, a variance crossover emerges: Hebbian ON starts with lower cross-seed variance than OFF, then surpasses it at generation~34. The crossover trend is monotonic (\r{ho} = 0.91, p < 10^{-6): plasticity's effect on behavioral variance reverses over evolutionary time, initially compressing diversity (consistent with prior predictions) then expanding it as evolved Perception differences are amplified through imagination -- a feedback loop that mutation alone cannot sustain. The result is structured behavioral divergence: ev
arXiv:2604.03565v1 Announce Type: new Abstract: Can lifetime learning expand behavioral diversity over evolutionary time, rather than collapsing it? Prior theory predicts that plasticity reduces variance by buffering organisms against environmental noise. We test this in a competitive domain: chess agents with eight NEAT-evolved neural modules, Hebbian within-game plasticity, and a desirability-domain signal chain with imagination. Across 10~seeds per Hebbian condition, a variance crossover emerges: Hebbian ON starts with lower cross-seed variance than OFF, then surpasses it at generation~34. The crossover trend is monotonic (\r{ho} = 0.91, p < 10^{-6): plasticity's effect on behavioral variance reverses over evolutionary time, initially compressing diversity (consistent with prior predictions) then expanding it as evolved Perception differences are amplified through imagination -- a feedback loop that mutation alone cannot sustain. The result is structured behavioral divergence: evolved agents select different moves on the same positions (62\% disagreement), develop distinct opening repertoires, piece preferences, and game lengths. These are not different sampling policies -- they are reproducible behavioral signatures (ICC > 0.8) with interpretable signal chain configurations. Three regimes appear depending on opponent type: exploration (Hebbian ON, heterogeneous opponent), lottery (Hebbian OFF, elitism lock-in), and transparent (same-model opponent, brain self-erasure). The transparent regime generates a falsifiable prediction: self-play systems may systematically suppress behavioral diversity by eliminating the heterogeneity that personality requires. \textbf{Keywords: Baldwin Effect, neuroevolution, NEAT, Hebbian learning, chess, cognitive architecture, personality emergence, imagination
Executive Summary
This article presents a groundbreaking study on the Baldwin Effect in neuroevolved chess agents, exploring the relationship between lifetime learning and behavioral diversity. The authors propose that plasticity can initially compress diversity but eventually expand it as evolved perception differences are amplified through imagination. The study reveals three regimes of the Baldwin Effect: exploration, lottery, and transparent, with the transparent regime generating a falsifiable prediction that self-play systems may suppress behavioral diversity. The findings have significant implications for the emergence of personality in artificial systems.
Key Points
- ▸ The Baldwin Effect can lead to the expansion of behavioral diversity over evolutionary time, rather than its collapse.
- ▸ Hebbian plasticity can initially compress diversity but eventually expand it as evolved perception differences are amplified through imagination.
- ▸ Three regimes of the Baldwin Effect are identified: exploration, lottery, and transparent, each with distinct characteristics.
Merits
Strength in Theoretical Framework
The article presents a well-structured theoretical framework that builds on prior research in the field, providing a clear understanding of the Baldwin Effect in neuroevolved systems.
Methodological Rigor
The authors employ a rigorous methodological approach, using a large number of seeds and a competitive domain to test their hypotheses, increasing the reliability of their findings.
Insight into Personality Emergence
The study provides valuable insights into the emergence of personality in artificial systems, highlighting the importance of plasticity and imagination in shaping behavioral diversity.
Demerits
Limited Generalizability
The findings may not be directly generalizable to other domains or systems, as the study is specifically focused on neuroevolved chess agents.
Need for Further Exploration
The transparent regime's prediction that self-play systems may suppress behavioral diversity requires further exploration and validation in other contexts.
Expert Commentary
The study presents a significant advancement in our understanding of the Baldwin Effect in neuroevolved systems, highlighting the importance of plasticity and imagination in shaping behavioral diversity. The findings have far-reaching implications for the development of artificial systems, cognitive architectures, and artificial general intelligence. While the study's limitations should be acknowledged, the methodological rigor and theoretical framework employed provide a solid foundation for future research in this area. The transparent regime's prediction warrants further exploration and validation, as it has significant implications for the development of autonomous systems.
Recommendations
- ✓ Future studies should investigate the Baldwin Effect in other domains and systems to determine the generalizability of the findings.
- ✓ The transparent regime's prediction should be tested in other contexts to validate its implications for the development of autonomous systems.
Sources
Original: arXiv - cs.AI