ArticleBiology letters2021
'Dunbar's number' deconstructed.
Article in Biology letters, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 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
10 citing papers in PubMed.
- AI agents can coordinate via majority-following beyond human scale.Science advances · 2026Article
- Implementation of Web-Based Respondent-Driven Sampling to Recruit Users of Electronic Nicotine Delivery Systems in Brazil: Cross-Sectional Survey.JMIR formative research · 2026Article
- The Evolutionary Psychology of Breaking Informal Versus Formal Contracts: Effects of Group Size and Area of Upbringing.Behavioral sciences (Basel, Switzerland) · 2025Article
- Social and spatial drivers of the multitiered structure of zebra finch social networks.Proceedings. Biological sciences · 2025Article
- Unveiling the social fabric through a temporal, nation-scale social network and its characteristics.Scientific reports · 2025Article
- From fossils to mind.Communications biology · 2023Review
- Social bonds are related to health behaviors and positive well-being globally.Science advances · 2023Article
- Sociality predicts orangutan vocal phenotype.Nature ecology & evolution · 2022Article
- Comparative connectomics of the primate social brain.NeuroImage · 2021Review
- 'Dunbar's number' deconstructed.Biology letters · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
A widespread and popular belief posits that humans possess a cognitive capacity that is limited to keeping track of and maintaining stable relationships with approximately 150 people. This influential number, 'Dunbar's number', originates from an extrapolation of a regression line describing the relationship between relative neocortex size and group size in primates. Here, we test if there is statistical support for this idea. Our analyses on complementary datasets using different methods yield wildly different numbers. Bayesian and generalized least-squares phylogenetic methods generate approximations of average group sizes between 69-109 and 16-42, respectively. However, enormous 95% confidence intervals (4-520 and 2-336, respectively) imply that specifying any one number is futile. A cognitive limit on human group size cannot be derived in this manner.
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.