ArticleiScience2026
Ecological not social factors explain brain size in cephalopods.
Article in iScience, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
3 citing papers in PubMed.
- Evolution of a core ribosomal innovation in octopus.Current biology : CB · 2026Article
- Evolution of a core ribosomal innovation in octopus.bioRxiv : the preprint server for biology · 2026Article
- Embodied cognitive evolution and the limits of convergence.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2025Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Social factors have been argued to be the main selection pressure for the evolution of large brains and complex behavior, but many cephalopods live largely solitary, semelparous, short lives. This suggests that the large brains found in cephalopods are not the result of social selection pressures. Here, we derive specific, preregistered predictions from the "Asocial Brain Hypothesis" (ABH; an untested extension of the cultural brain hypothesis formal model), and evaluate those predicted associations using a new comparative dataset on brain size alongside social, ecological, and life history factors. Consistent with the ABH and other hypotheses predicting that ecological factors should be the primary selection pressure with larger brains in more calorie-rich complex ecologies, we find that shallower and benthic (seafloor) habitats are associated with larger brain sizes, and that measures of sociality are not. Our findings are not interpreted as causal, but are consistent with ecological hypotheses for brain evolution.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.