# Big Brains and Changing Environments: Cause or Consequence?

arXiv: https://arxiv.org/abs/2609.15569 · HTML: https://mlsanity.com/paper/2609.15569/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 1 of its 35 references that are in the map.
- First posted on arXiv 14 Sep 2026.

## Builds on (most cited first, 1 of 1)

- [Energy Costs and Neural Complexity Evolution in Changing Environments](https://mlsanity.com/paper/2511.20018/) (2025)

## Abstract (arXiv)

Large brains are metabolically costly, and associations with changing environments do not imply they evolved there, as the Cognitive Buffer Hypothesis (CBH) would suggest. They may instead evolve in stable conditions and later facilitate colonization of changing environments. Using neuro-evolution in an artificial seasonal foraging task, we compared agents evolving exclusively in changing environments to agents first evolved in static environments before transitioning. Results show that larger neural networks in dynamic environments arise mainly from prior static evolution, achieving superior performance under unpredictable changes. Our results challenge strict CBH predictions, provide agent-based (computational) support for a colonization-based account and highlight the role of evolutionary history in brain size evolution.