Source Paper
Evan L. MacLean, Brian Hare, Charles L. Nunn, Elsa Addessi, Federica Amici et al.
Proceedings of the National Academy of Sciences • 2014
Significance Although scientists have identified surprising cognitive flexibility in animals and potentially unique features of human psychology, we know less about the selective forces that favor cognitive evolution, or the proximate biological mechanisms underlying this process. We tested 36 species in two problem-solving tasks measuring self-control and evaluated the leading hypotheses regarding how and why cognition evolves. Across species, differences in absolute (not relative) brain volume best predicted performance on these tasks. Within primates, dietary breadth also predicted cognitive performance, whereas social group size did not. These results suggest that increases in absolute brain size provided the biological foundation for evolutionary increases in self-control, and implicate species differences in feeding ecology as a potential selective pressure favoring these skills.
Objective: Quantitatively compare cognitive performance across 567 individuals representing 36 species on two problem-solving tasks measuring self-control and executive function to test evolutionary hypotheses about cognitive evolution
This is a Comparative Cognitive Performance Assessment protocol using 36 species (comparative study across multiple species) as the model organism. The procedure involves 5 procedural steps. Extracted from a 2014 paper published in Proceedings of the National Academy of Sciences.
Model and subjects
36 species (comparative study across multiple species) • Not specified • unknown • Not specified • Not specified • 567
Study window
Estimated timing pending
Core workflow
Subject Recruitment and Participation • Problem-Solving Task Administration • Brain Volume Measurement
Primary readouts
Key equipment and reagents
Verified items
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Direct vendor links
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Recruited 567 individuals representing 36 species for cognitive testing
Note: Multi-site collaborative study involving researchers from multiple institutions across different countries
“quantitatively comparing the cognitive performance of 567 individuals representing 36 species on two problem-solving tasks measuring self-control”
Administered two problem-solving tasks measuring self-control and executive function to all subjects
Note: Tasks designed to measure inhibitory control and self-control across diverse species
“two problem-solving tasks measuring self-control”
Measured absolute brain volume and brain volume controlling for body mass for each species
Note: Data used to test proximate evolutionary explanations for cognitive differences
“absolute and relative brain volume and at the ultimate level by differences in social and dietary complexity”
Collected dietary breadth and social group size data for primate species
Note: Data used to test ultimate evolutionary explanations for cognitive differences within primates
“Within primates, dietary breadth but not social group size was a strong predictor of species differences in self-control”
Conducted phylogenetic analysis to evaluate relationships between brain volume, dietary breadth, and cognitive performance
Note: Analysis tested leading hypotheses regarding how and why cognition evolves
“Phylogenetic analysis revealed that absolute brain volume best predicted performance across species and accounted for considerably more variance than brain volume controlling for body mass”
This section explains what the experiment is doing, which readouts matter, what the data artifacts usually look like, and how the analysis should flow from raw capture to reported result.
Quantitatively compare cognitive performance across 567 individuals representing 36 species on two problem-solving tasks measuring self-control and executive function to test evolutionary hypotheses about cognitive evolution
Objective
Quantitatively compare cognitive performance across 567 individuals representing 36 species on two problem-solving tasks measuring self-control and executive function to test evolutionary hypotheses about cognitive evolution
Subjects
From paper36 species (comparative study across multiple species) • Not specified • unknown • Not specified • Not specified
Sample count
From paper567
Cohort notes
From paperStudy includes primates and non-primates; dietary breadth and social group size measured within primates
Subject Recruitment and Participation (Not specified)
Problem-Solving Task Administration (Not specified)
Brain Volume Measurement (Not specified)
Ecological Data Collection (Not specified)
Performance on two problem-solving tasks measuring self-control
From paperPhylogenetic analysis to test evolutionary hypotheses; comparison of absolute brain volume versus relative brain volume as predictors of cognitive performance; evaluation of dietary breadth and social group size as predictors of cognitive performance within primates
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Performance on tasks measuring executive function
From paperPhylogenetic analysis to test evolutionary hypotheses; comparison of absolute brain volume versus relative brain volume as predictors of cognitive performance; evaluation of dietary breadth and social group size as predictors of cognitive performance within primates
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Absolute brain volume
From paperPhylogenetic analysis to test evolutionary hypotheses; comparison of absolute brain volume versus relative brain volume as predictors of cognitive performance; evaluation of dietary breadth and social group size as predictors of cognitive performance within primates
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Brain volume controlling for body mass
From paperPhylogenetic analysis to test evolutionary hypotheses; comparison of absolute brain volume versus relative brain volume as predictors of cognitive performance; evaluation of dietary breadth and social group size as predictors of cognitive performance within primates
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Performance on two problem-solving tasks measuring self-control
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Performance on tasks measuring executive function
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Absolute brain volume
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Brain volume controlling for body mass
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Acquisition
Collect raw experimental outputs with enough metadata to preserve sample identity, condition, and timing.
Preprocessing / cleaning
Phylogenetic analysis to test evolutionary hypotheses; comparison of absolute brain volume versus relative brain volume as predictors of cognitive performance; evaluation of dietary breadth and social group size as predictors of cognitive performance within primates
Scoring or quantification
Quantify the primary readouts for this experiment: Performance on two problem-solving tasks measuring self-control; Performance on tasks measuring executive function; Absolute brain volume; Brain volume controlling for body mass.
Statistical comparison
Statistical method not yet structured for this page.
Reporting output
Report representative outputs alongside summary comparisons for Performance on two problem-solving tasks measuring self-control, Performance on tasks measuring executive function, Absolute brain volume, Brain volume controlling for body mass.
Source links and direct wording from the methods section for validation and deeper review.
Citation
Evan L. MacLean et al. (2014). The evolution of self-control. Proceedings of the National Academy of Sciences
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Evidence Quotes
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Evidence
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Canonical Sync
Pending
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