The DOI matches its Crossref record; 226 of the 226 references it cites were found in a registry or an index; none of the 46 sources its claims cite is checked for support yet.
The evolution of self-control.
Open accessAbstract
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.
Overview
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Written from the paper’s full text.
TL;DR
This study experimentally compared self-control across 567 individuals from 36 mammal and bird species using two problem-solving tasks and phylogenetic comparative methods. It found that absolute brain volume, not relative brain volume, best predicted performance, and that within primates dietary breadth—but not social group size—was strongly associated with self-control.
Key findings
- Across species, absolute brain volume (endocranial volume, ECV) was a robust predictor of self-control, explaining substantial variance on the cylinder task and composite score (r² = 0.43–0.60); residual brain volume explained only 3% of variance in composite scores.
- Within primates, absolute brain volume was the best predictor (r² = 0.55–0.68), and dietary breadth also covaried strongly with self-control (r² = 0.68); a multiple regression including both ECV and dietary breadth explained 82% of variance in primate composite scores.
- Social group size (population and foraging group size) and percent fruit in diet were not significant predictors of primate self-control, whereas observational measures such as social learning, extractive foraging, tool use, tactical deception, and g_s covaried positively with experimental scores.
- Performance on the two tasks was strongly correlated across species (r = 0.53, n = 23, P < 0.01), and scores from multiple populations of the same species were highly correlated (cylinder: r = 0.95, n = 5, P = 0.01; A-not-B: r = 0.87, n = 6, P = 0.03).
Methods
- The study tested 567 individuals representing 36 species on two self-control tasks: the A-not-B task (27 species, n = 344) and the cylinder task (32 species, n = 439), using standardized pretest criteria and species-level mean performance.
- Phylogenetic generalized least squares (PGLS) was used to test associations between cognitive performance and neuroanatomical predictors (absolute ECV, residual brain volume, encephalization quotient) and socioecological predictors (group size, frugivory, dietary breadth), accounting for phylogenetic nonindependence.
- For primates, the authors also fit a multiple regression with absolute ECV and dietary breadth as predictors of composite cognitive scores, and reconstructed ancestral states along the primate phylogeny.
Limitations
- The paper states that analyses were restricted to whole-brain volume measures because comparative data on finer neuroanatomical substrates (e.g., neuron counts, regional volumes, functional connectivity) were limited.
- The paper cautions that single-task species data must be interpreted cautiously, citing the Asian elephant’s A-not-B performance, and notes that task features may be more appropriate for some species than others.
- The paper states that ecological analyses focused on primates because they were best represented and had systematically compiled ecological data; it also notes that more nuanced social/ecological measures may be needed to detect relationships. Evident from the text: the design is correlational, taxonomic sampling is uneven across groups, and the composite score was available for only 23 species.
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Claims the paper makes
63 Own result · 15 Not checked yet · 8 Own interpretation · 7 Own method
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Within primates the analysis using EQ as a pre-dictor of composite scores was similar to that using ECV residuals (β = 0.24, t 13 = 1.65,P = 0.06, λ = 0.66, r 2 = 0.17).”
§ The evolution of self-control > Results
plaincorrelationaln = 309 ·- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The percent of fruit in a species' diet was not a significant predictor of any of the cognitive measures (Fig. 3, Table 2, and Table S7).”
§ The evolution of self-control > Results
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Across species, absolute brain volume (measured as ECV) was a robust predictor of performance (Fig. 2 and Table 2), supporting the predictions of the cortical reorganization hypothesis.”
§ The evolution of self-control > Results
boostedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Residual brain volume was not a significant predictor of any of these measures (Table 2)”
§ The evolution of self-control > Results
plainn = 258- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Supplemental analyses involving home range size, day journey length, the defensibility index, and substrate use revealed no significant associations (SI Text and Fig. S1).”
§ The evolution of self-control > Results
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Across species and accounting for phylogeny, performance on the two tasks was strongly correlated (r = 0.53, n = 23, P < 0.01).”
§ The evolution of self-control > Results
boostedcorrelationaln = 23- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“However, dietary breadth covaried strongly with our measures of self-control (Fig. 3, Table 2, and Table S7).”
§ The evolution of self-control > Results
boostedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Controlling for observational research effort, our experimental measures covaried positively with reports of innovation, extractive foraging, tool use, social learning, and tactical deception in primates (Table 2, Table S7, and SI Text).”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For both tasks, scores from multiple populations of the same species (collected by different researchers at different sites) were highly correlated (cylinder task: r = 0.95, n = 5, P = 0.01; A-not-B task: r = 0.87, n = 6, P = 0.03; SI Text and Table S6).”
§ The evolution of self-control > Results
plaincorrelationaln = 6 ·- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Thus, while correlated with one another (t = 3.04, P < 0.01, λ = 0, r 2 = 0.32), both brain volume and dietary complexity account for unique components of variance in primate cognition, together explaining the majority of interspecific variation on these tasks.”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
- It may state two separate claims as one. 21
- Probably not a substantial claim. 7
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Maximum likelihood reconstruction of ancestral states implies gradual cognitive evolution in the lineage leading to apes, with a convergence between apes and capuchin monkeys (Fig. 4 and SI Text).”
§ The evolution of self-control > Results
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In contrast to the analysis across all species, residual brain volume was predictive of performance on both tasks within primates, although it explained much less variance than absolute brain volume (r 2 = 0.18-0.30;Fig. 3 and Table 2).”
§ The evolution of self-control > Results
plaincorrelationaln = 309- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This model explained 82% of variance in performance between species with significant and positive coefficients for both absolute ECV and dietary breadth, controlling for the effects of one another (ECV: t 11 = 3.30, P < 0.01; dietary breadth: t 11 = 3.02, P < 0.01; λ = 0.00, r 2 = 0.82).”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Across the entire sample, residual brain volume was far less predictive than absolute brain volume: it explained only 3% of variance in composite scores, and was a significant predictor of performance in only one of the tasks (Table 2, SI Text, and Fig. 2).”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
In the paper
“Neither measure of group size was associated with task performance (Fig. 3, Table 2, and Table S7), echoing findings using observational data on behavioral flexibility (92).”
§ The evolution of self-control > Results
What the sources say
- Not checked yetcites [92] source
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“ECV covaried positively with performance on the cylinder task and the composite score and explained substantial variance in performance (r 2 = 0.43-0.60;Table 2).”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Within the nonprimate species, ECV was again the best predictor of self-control, and was significantly and positively associated with composite scores and scores on the cylinder task, but not the A-not-B task (Table 2).”
§ The evolution of self-control > Results
plaincorrelationaln = 258 ·- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This association was much weaker for the A-not-B task, reflecting that the largestbrained species (Asian elephant) had the lowest score on this measure (Fig. 2 and Table 2).”
§ The evolution of self-control > Results
plaincorrelationalSingle case- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Phylogenetic analyses revealed that scores were more similar among closely related species, with the maximum likelihood estimate of λ, a measure of phylogenetic signal, significantly greater than zero in most cases (Table 1).”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“EQ was positively related to composite scores across species (β = 0.28, t 21 = 3.23, P < 0.01, λ = 0, r 2 = 0.33) but again explained far less variance than absolute brain volume.”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Within primates, absolute brain volume was the best predictor of performance across tasks and explained substantial variation across species (r 2 = 0.55-0.68;Fig. 3 and Table 2).”
§ The evolution of self-control > Results
plaincorrelationaln = 309- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“First, a comparison of models using only body mass or ECV as the predictor of composite scores yielded stronger support for the ECV model both in an analysis across all species [change in the Akaike information criterion (Δ AICc ) = 0.77], and within primates (Δ AICc = 3.12).”
§ The evolution of self-control > Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In contrast, residual brain volume was only weakly related, and social group size was unrelated, to variance in selfcontrol.”
§ The evolution of self-control > Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Thus, while correlated with one another (t = 3.04, P < 0.01, λ = 0, r 2 = 0.32), both brain volume and dietary complexity account for unique components of variance in primate cognition, together explaining the majority of interspecific variation on these tasks.”
§ The evolution of self-control > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
- Rests on an assumption: The composite score averaging performance across tasks is a valid broader index of self-control.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“In both tasks, all species were required to meet the same pretest criteria, demonstrating a basic understanding of the task, and allowing meaningful comparison of test data across species.”
§ The evolution of self-control > Methods
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“To control for the nonindependence of species level data, we used phylogenetic generalized least squares (PGLS) to test the association between performance on the cognitive tasks and the explanatory variables associated with each hypothesis.”
§ The evolution of self-control > Results
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
None of the sources cited for this claim have been checked yet.
In the paper
“The foraging hypothesis posits that dietary complexity, indexed by field reports of dietary breadth and reliance on fruit (a spatiotemporally distributed resource), was the primary driver of primate cognitive evolution (151-154).”
§ The evolution of self-control > Significance
What the sources say
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
None of the sources cited for this claim have been checked yet.
In the paper
“In contrast, the encephalization hypothesis argues that an increase in brain volume relative to body size was of primary importance (108, 110, 111, 123).”
§ The evolution of self-control > Significance
What the sources say
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
None of the sources cited for this claim have been checked yet.
In the paper
“The social intelligence hypothesis proposes that increased social complexity (frequently indexed by social group size) was the major selective pressure in primate cognitive evolution (6, 44, 48, 50, 87, 115, 120, 125-141).”
§ The evolution of self-control > Significance
What the sources say
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Thus, the relationship between absolute brain volume and self-control may be most pronounced in the primate species in our sample, and may not generalize to all other large-brained animals (e.g., whales, elephants), or taxa whose brains are organized differently than primates (e.g., birds).”
§ The evolution of self-control > Discussion
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“This research was approved by the Duke University Institutional Animal Care and Use Committee (protocol numbers A303-11-12, A199-11-08, and A055-11-03).”
§ The evolution of self-control > Methods
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Thus, multiple lines of evidence implicate selection for brain volume (and organization) independent of selection for body size, and our data illustrate the cognitive consequences of these evolutionary trends.”
§ The evolution of self-control > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Our findings also implicate dietary breadth as an important ecological correlate, and potential selective pressure for the evolution of these skills.”
§ The evolution of self-control > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
In the paper
“Second, the number of neurons in primate brains scales isometrically with brain size, indicating selection for constant neural density and neuron size, a scaling relationship that contrasts with other orders of animals (100).”
§ The evolution of self-control > Discussion
What the sources say
- Not checked yetcites [100] source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“The cortical reorganization hypothesis suggests that selection for absolutely larger brains-and concomitant cortical reorganization-was the predominant mechanism supporting cognitive evolution (77, 91, 100-106, 120).”
§ The evolution of self-control > Significance
What the sources say
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“The data reported here likely represent relatively accurate estimates of species-typical cognition because we collected data from large samples within each species (mean n = 15.3 ± 2.0 subjects per species, range = 6-66), scores from multiple populations of the same species were highly correlated, and performance was not associated with previous experience in cognitive tasks (SI Text).”
§ The evolution of self-control > Discussion
hedgedcorrelationaln = 15- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The two problem-solving tasks validly measure self-control across species.
None of the sources cited for this claim have been checked yet.
In the paper
“In humans, self-control has been linked to health, economic, social, and academic achievement, and is known to be heritable (170-172).”
§ The evolution of self-control > Significance
What the sources say
boostedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“For example, the best performing species in our sample were predominantly anthropoid primates, species that have evolved unique prefrontal areas that are thought to provide a cognitive advantage in foraging decisions that rely on executive function (176-178).”
§ The evolution of self-control > Discussion
What the sources say
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
The paper relies on this without support.
The two problem-solving tasks validly measure self-control across species.
“We experimentally evaluated these major evolutionary explanations by quantitatively comparing the cognitive performance of 567 individuals representing 36 species on two problem-solving tasks measuring self-control.”
The paper relies on this without support.
The composite score averaging performance across tasks is a valid broader index of self-control.
“Because the two tasks assessed complementary but not identical abilities, the composite score serves as a broader index of self-control across tasks.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The cited source says what the claim attributes to it.
In the citing paper
“Absolute brain size is often a reasonable predictor of specific cognitive abilities in studies that did not use the measure based on cognitive equivalence [Benson-Amran et al., 2013;MacLean et al., 2014;Horschler et al., 2019].”
From A Farewell to the Encephalization Quotient: A New Brain Size Measure for Comparative Primate Cognition (2021) · cites this paper as MacLean et al., 2014
In the citing paper
“In primates, absolute brain size predicts neuron number and is strongly correlated with the ability to inhibit prepotent responses (MacLean et al., 2014).”
From Hypotheses for the Evolution of Reduced Reactive Aggression in the Context of Human Self-Domestication (2019) · cites this paper as MacLean et al., 2014
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Rated major: it would touch a result — a value a result rests on, reported and recomputed p-values on opposite sides of the significance level, two passages that conflict with no sign which is right, or a cited work retracted before this paper was published.
In the paper
§ The evolution of self-control > Discussion
“even the most predictive neuroanatomical measures failed to account for more than 30% of cognitive variance across species in this study.”
§ The evolution of self-control > Methods
“| | Absolute brain volume | Composite | 5.67 | 21 | <0.01 | 0.60 | 0.00 |”
Rated minor: it would not touch a result — a value no result rests on, a p-value that stays on the same side of the significance level, or a conflict that is clerical, resolved elsewhere in the paper, or outside its own findings.
In the paper
§ The evolution of self-control > Methods
“In both tasks and in the composite measure, ECV was a significant predictor of self-control.”
§ The evolution of self-control > Methods
“| | Absolute brain volume | A-not-B | 1.03 | 25 | 0.16 | 0.04 | 0.69 |”
Citations
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Self-citationOrigins of spatial, temporal and numerical cognition: Insights from comparative psychology
Haun, D. B. M., Jordan, F. M., Vallortígara, G., & Clayton, N. S. (2010) · Trends in Cognitive Sciences · doi:10.1016/j.tics.2010.09.006 · Cited by 68
Self-citationPlatt, M. L., Brannon, E. M., Briese, T. L., & French, J. A. (1996) · Animal Learning & Behavior · doi:10.3758/bf03199010 · Cited by 68
Self-citationThe modulatory of social intelligence
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Cranial capacity and neuron number: A critique and proposal
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Foraging Cognition in Nonhuman Primates
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Big brains are not enough: performance of three parrot species in the trap-tube paradigm
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The Modularity of Social Intelligence
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Embracing covariation in brain evolution
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A Modular Mind? A Test Using Individual Data from Seven Primate Species
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Self-citationWebb, B. H. (2012) · Philosophical Transactions of the Royal Society B Biological Sciences · doi:10.1098/rstb.2012.0218 · Cited by 52
A socioecological perspective on primate cognition, past and present
Cunningham, E. P., & Janson, C. H. (2007) · Animal Cognition · doi:10.1007/s10071-007-0078-3 · Cited by 49
Sex and species differences in spatial memory in food-storing kangaroo rats
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Self-citationSeyfarth, R. M., & Cheney, D. L. (2002) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.082105099 · Cited by 46
Dietary quality and encephalization in platyrrhine primates
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Research works printed but not linked: 1
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Cited by
Sorted by citations
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Self-citation
Metadata
- Authors
- MacLean, E. L., Hare, B., Nunn, C. L., Addessi, E., Amici, F., Anderson, R. C., Aureli, F., Baker, J. M., Bania, A. E., Barnard, A. M., Boogert, N. J., Brannon, E. M., Bray, E. E., Bray, J., Brent, L. J. N., Burkart, J. M., Call, J., Cantlon, J. F., Cheke, L. G., Clayton, N. S., Delgado, M. M., DiVincenti, L. J., Fujita, K., Herrmann, E., Hiramatsu, C., Jacobs, L. F., Jordan, K. E., Laude, J. R., Leimgruber, K. L., Messer, E. J. E., de A. Moura, A. C., Ostojić, L., Picard, A., Platt, M. L., Plotnik, J. M., Range, F., Reader, S. M., Reddy, R. B., Sandel, A. A., Santos, L. R., Schumann, K., Seed, A. M., Sewall, K. B., Shaw, R. C., Slocombe, K. E., Su, Y., Takimoto, A., Tan, J., Tao, R., van Schaik, C. P., Virányi, Z., Visalberghi, E., Wade, J. C., Watanabe, A., Widness, J., Young, J. K., Zentall, T. R., & Zhao, Y.
- Affiliations
- Departments of aEvolutionary Anthropology,
- Institut des Sciences Cognitives Marc Jeannerod (FR)
- National Research Council (IT)
- Max Planck Institute for Evolutionary Anthropology (DE)
- Duke University (US)
- Universidad Veracruzana (MX)
- Stanford Medicine (US)
- Smithsonian Institution (US)
- Department of Brain and Cognitive Science and
- University of St Andrews (GB)
- Psychology and Neuroscience, and
- University of Pennsylvania (US)
- University of Zurich (CH)
- University of Cambridge (GB)
- Department of Psychology and
- University of Rochester (US)
- Kyoto University (JP)
- University of California, Berkeley (US)
- Departments of vPsychology and
- University of Kentucky (US)
- Yale University (US)
- Departamento Engenharia e Meio Ambiente, Universidade Federal da Paraiba, 58059-900, João Pessoa, Brazil;
- University of York (GB)
- University of Veterinary Medicine Vienna (AT)
- McGill University (CA)
- University of Michigan (US)
- Peking University (CN)
- Anthropological Institute and Museum, University of Zurich, 8057 Zurich, Switzerland;
- Utah State University (US)
- ORCID
- MacLean, Evan L.
- Nunn, Charles L.
- Addessi, Elsa
- Amici, Federica
- Anderson, Rindy C.
- Aureli, Filippo
- Baker, Joseph M.
- Barnard, Allison M.
- Boogert, Neeltje J.
- Brannon, Elizabeth M.
- Bray, Emily E.
- Bray, Joel
- Brent, Lauren J. N.
- Burkart, Judith M.
- Call, Josep
- Cantlon, Jessica F.
- Cheke, Lucy G.
- Clayton, Nicola S.
- Delgado, Mikel M.
- Herrmann, Esther
- Hiramatsu, Chihiro
- Jacobs, Lucia F.
- Jordan, Kerry E.
- Leimgruber, Kristin L.
- Messer, Emily J. E.
- Ostojić, Ljerka
- Platt, Michael L.
- Plotnik, Joshua M.
- Range, Friederike
- Reader, Simon M.
- Reddy, Rachna B.
- Sandel, Aaron A.
- Santos, Laurie R.
- Seed, Amanda M.
- Sewall, Kendra B.
- Shaw, Rachael C.
- Slocombe, Katie E.
- Su, Yanjie
- Tan, Jingzhi
- Virányi, Zsófia
- Visalberghi, Elisabetta
- Widness, Jane
- Young, Julie K.
- Zentall, Thomas R.
- Venue
- Proceedings of the National Academy of Sciences
- Publisher
- National Academy of Sciences
- Published
- 2014-04-21
- Volume
- 111
- Issue
- 20
- Pages
- E2140-8
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- PMC
- PMC4034204
- OpenAlex
- W2100359507
- Cited by
- 819
- References
- 226
- Citations by year
- 2026: 33 · 2025: 43 · 2024: 80 · 2023: 41 · 2022: 94 · 2021: 91 · 2020: 91 · 2019: 92 · 2018: 74 · 2017: 63 · 2016: 68 · 2015: 31 · 2014: 17
- FWCI
- 88.52
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Proceedings of the National Academy of Sciences (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Digital Commons - USU (Utah State University) (submittedVersion)
- eScholarship (California Digital Library) (submittedVersion)
- eScholarship@McGill (McGill) (submittedVersion)
- St Andrews Research Repository (St Andrews Research Repository) (submittedVersion)
- VTechWorks (Virginia Tech) (submittedVersion)
- Zurich Open Repository and Archive (University of Zurich) (submittedVersion)
- Funders
- National Science Foundation (0923791, 220020242, 1106401, NSF-BCS-25172, 1028319, 0905606, FP/2007‐2013)
- U.S. Department of Agriculture
- Alfred P. Sloan Foundation
- James S. McDonnell Foundation (220020242)
- National Evolutionary Synthesis Center (EF0905606, 0905606)
- European Commission (2007–2013, 012-984, FP/2007/2013)
- National Natural Science Foundation of China (973 Program, FP/2007-2013, 31170995)
- Vienna Science and Technology Fund (CS11-026)
- Austrian Science Fund (P 21244)
- Royal Canin (311870)
- Consiglio Nazionale delle Ricerche
- National Institutes of Health (5r03hd070649-02, DGE-1106401, 1106401, FP/2007-2013)
- Japan Society for the Promotion of Science (26119514, 20220004, 10J04395, 25118002, 25240020)
- National Key Research and Development Program of China (2010CB833904)
- National Institute of Mental Health (R01MH089484, R01MH096875)
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (5 R03 HD070649-02, R03 HD070649)
- National Wildlife Research Center
- FP7 Ideas: European Research Council (311870)
- Topics
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Primate Behavior and Ecology
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Evolutionary Psychology and Human Behavior
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Animal Behavior and Reproduction
- Keywords
- self-control, cognitive evolution, brain size, diet breadth, social group size, primate cognition, problem solving, cortical reorganization, phylogenetic comparative analysis, evolutionary neurobiology
- MeSH terms
- Animals, Brain, Cognition, Diet, Biological Evolution, Humans, Learning, Organ Size, Phylogeny, Primates, Problem Solving, Selection, Genetic, Social Behavior, Species Specificity, Models, Statistical, Likelihood Functions
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-10, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-10 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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