ArticleScientific reports2022
The adaptive significance of human scleral brightness: an experimental study.
Article in Scientific reports, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 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
8 citing papers in PubMed, 13 citations in OpenAlex.
- The right eye for fixations: Eye asymmetries modulate gaze patterns towards speakers.Psychonomic bulletin & review · 2026Article
- Visual attention and subjective preference in mascot design: evidence from eye-tracking, ratings, and fsQCA.Frontiers in psychology · 2026Article
- Scleral exposure influences social judgments of trustworthiness, attractiveness, sociability, and social rank in White faces.PloS one · 2026Article
- Look past the cooperative eye hypothesis: reconsidering the evolution of human eye appearance.Biological reviews of the Cambridge Philosophical Society · 2025Review
- The Apemen Faces Database (ApeFD).Scientific data · 2025Article
- Photoregulatory functions drive variation in eye coloration across macaque species.Scientific reports · 2024Article
- How (and why) languages became more complex as we evolved more prosocial: the human self-domestication view.Frontiers in psychology · 2024Article
- Are dark-eyed dogs favoured by humans? Domestication as a potential driver of iris colour difference between dogs and wolves.Royal Society open science · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors at 4 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Homogeneously depigmented sclerae have long been proposed to be uniquely human-an adaptation to enable cooperative behaviour by facilitating interpersonal coordination through gaze following. However, recent evidence has shown that deeply pigmented sclerae also afford gaze following if surrounding a bright iris. Furthermore, while current scleral depigmentation is clearly adaptive in modern humans, it is less clear how the evolutionarily intermediate stages of scleral pigmentation may have been adaptive. In sum, it is unclear why scleral depigmentation became the norm in humans, while not so in sister species like chimpanzees, or why some extant species display intermediate degrees of pigmentation (as our ancestors presumably did at some point). We created realistic facial images of 20 individually distinct hominins with diverse facial morphologies, each face in the (i) humanlike bright sclera and (ii) generalised apelike dark sclera version. Participants in two online studies rated the bright-sclera hominins as younger, healthier, more attractive and trustworthy, but less aggressive than the dark-sclera hominins. Our results support the idea that the appearance of more depigmented sclerae promoted perceived traits that fostered trust, increasing fitness for those individuals and resulting in depigmentation as a fixed trait in extant humans.
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.