This study explores the relationship between brain size and cognitive abilities in primates, focusing on social learning, innovation, and tool use. Using data from 533 instances of innovation, 445 observations of social learning, and 607 episodes of tool use, the researchers found that these behaviors are positively correlated with species' relative and absolute "executive" brain volumes, after controlling for phylogeny and research effort. The findings suggest that social learning, innovation, and tool use frequencies are not in conflict with the idea of an evolutionary tradeoff between individual experience and social cues, but rather indicate that these abilities may have evolved together. The study also highlights the importance of behavioral flexibility in primate brain evolution, with the ability to learn from others, invent new behaviors, and use tools playing a pivotal role. The researchers used ecological measures of cognitive ability, such as innovation, social learning, and tool use, to assess behavioral flexibility. They found that these behaviors are closely linked to the size of the neocortex and striatum, collectively known as the "executive brain," which is thought to be responsible for cognitive processes like innovation and social learning. The study addresses the challenges of measuring learning and cognition across species, noting that experimental approaches can be biased and not representative of all species. Instead, the researchers used data on the incidence of complex traits associated with behavioral flexibility, which is considered a more reliable measure. They also controlled for phylogeny using independent contrasts and found that social learning, innovation, and tool use frequencies are positively correlated with executive brain volume. The study supports the idea that behavioral innovation and cultural transmission are central to the evolution of the human brain. It also challenges the notion that there is a tradeoff between social and asocial learning, suggesting that these abilities may have evolved together. The findings provide empirical support for the link between brain size and behavioral flexibility in mammals, and suggest that social learning and innovation may have been important processes in the evolution of large brains in primates.This study explores the relationship between brain size and cognitive abilities in primates, focusing on social learning, innovation, and tool use. Using data from 533 instances of innovation, 445 observations of social learning, and 607 episodes of tool use, the researchers found that these behaviors are positively correlated with species' relative and absolute "executive" brain volumes, after controlling for phylogeny and research effort. The findings suggest that social learning, innovation, and tool use frequencies are not in conflict with the idea of an evolutionary tradeoff between individual experience and social cues, but rather indicate that these abilities may have evolved together. The study also highlights the importance of behavioral flexibility in primate brain evolution, with the ability to learn from others, invent new behaviors, and use tools playing a pivotal role. The researchers used ecological measures of cognitive ability, such as innovation, social learning, and tool use, to assess behavioral flexibility. They found that these behaviors are closely linked to the size of the neocortex and striatum, collectively known as the "executive brain," which is thought to be responsible for cognitive processes like innovation and social learning. The study addresses the challenges of measuring learning and cognition across species, noting that experimental approaches can be biased and not representative of all species. Instead, the researchers used data on the incidence of complex traits associated with behavioral flexibility, which is considered a more reliable measure. They also controlled for phylogeny using independent contrasts and found that social learning, innovation, and tool use frequencies are positively correlated with executive brain volume. The study supports the idea that behavioral innovation and cultural transmission are central to the evolution of the human brain. It also challenges the notion that there is a tradeoff between social and asocial learning, suggesting that these abilities may have evolved together. The findings provide empirical support for the link between brain size and behavioral flexibility in mammals, and suggest that social learning and innovation may have been important processes in the evolution of large brains in primates.