ArticleAmerican journal of human biology : the official journal of the Human Biology Council2025
Intrasexual Selection for Upper Limb Length in Homo sapiens.
Article in American journal of human biology : the official journal of the Human Biology Council, 2025. 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.
- Throwing like a girl: a critique of past approaches and an illustrated proposal for a path forward.Biology of sex differences · 2025Review
- Facial width-to-height ratio predicts fighting success: A direct replication and extension of Zilioli et al. (2014).Aggressive behavior · 2022Article
- Human third-party observers accurately track fighting skill and vigour along their unique paths to victory.Scientific reports · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesSexual selection via contest competition has equipped countless organisms with weaponry in their appendages to overpower their opponents. Here, we tested (1) whether greater upper limb length-measured as span controlling for biacromial width-confers an advantage in contest competition among adult humans, (2) several possible means by which upper limb length might increase success in intrasexual contest competition, and (3) whether, consistent with male-male contest competition creating stronger selection pressures than female-female contest competition, male Homo sapiens have greater upper limb length.
methodsWe collected fight statistics and facial and body photographs from professional combatants (N = 715) in the Ultimate Fighting Championship (UFC; Study 1). Sexual dimorphism in upper limb length was then examined via diverse and demographically representative samples from four studies (total N = 6915), from Croatian adolescents and older Singaporean adults to United States Army personnel born across all major world regions (Studies 2a-2d).
resultsFirst, we found that greater upper limb length is associated with increased success in intrasexual contest competition, an effect driven by both the capacity to grapple opponents to submission and to knock opponents unconscious (Study 1). Second, we found unequivocal, cross-cultural evidence of unique sexual dimorphism in upper limb length after controlling for allometry: across four studies, men exhibited longer upper limbs than women (Studies 2a-2d).
conclusionUpper limb length may have been shaped by intrasexual selection, with implications across the biological, anthropological, and psychological sciences.
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.