This study investigates the relationship between the efficiency of functional brain networks and intellectual performance. Using graph theory, the researchers analyzed resting-state functional magnetic resonance imaging (fMRI) data from 19 healthy subjects to examine the organization of brain networks and its association with intelligence. They found a strong negative correlation between the normalized characteristic path length (λ) of the resting-state brain network and IQ, suggesting that more efficient global communication within the brain network is associated with higher intellectual performance. The most pronounced effects were observed in frontal and parietal regions. The brain network was found to exhibit a small-world organization, characterized by high local clustering and efficient global communication. The study also revealed that the normalized path length of specific brain regions, such as the medial prefrontal cortex, precuneus/posterior cingulate gyrus, and bilateral inferior parietal regions, showed significant negative correlations with IQ. These regions are part of the default mode network, which is involved in cognitive and emotional processes. The findings indicate that the efficiency of functional brain networks is closely related to intellectual performance. The study also highlights the importance of global communication efficiency in the brain, as opposed to local information processing or the total number of connections. The results suggest that efficient integration of information across different brain regions is crucial for higher intellectual performance. Additionally, the study found that white matter organization, particularly in the cingulum tract, is positively associated with IQ, further supporting the role of both structural and functional connectivity in intelligence. The study underscores the complex interplay between brain network organization and cognitive performance, emphasizing the importance of efficient global communication in the brain for intellectual abilities.This study investigates the relationship between the efficiency of functional brain networks and intellectual performance. Using graph theory, the researchers analyzed resting-state functional magnetic resonance imaging (fMRI) data from 19 healthy subjects to examine the organization of brain networks and its association with intelligence. They found a strong negative correlation between the normalized characteristic path length (λ) of the resting-state brain network and IQ, suggesting that more efficient global communication within the brain network is associated with higher intellectual performance. The most pronounced effects were observed in frontal and parietal regions. The brain network was found to exhibit a small-world organization, characterized by high local clustering and efficient global communication. The study also revealed that the normalized path length of specific brain regions, such as the medial prefrontal cortex, precuneus/posterior cingulate gyrus, and bilateral inferior parietal regions, showed significant negative correlations with IQ. These regions are part of the default mode network, which is involved in cognitive and emotional processes. The findings indicate that the efficiency of functional brain networks is closely related to intellectual performance. The study also highlights the importance of global communication efficiency in the brain, as opposed to local information processing or the total number of connections. The results suggest that efficient integration of information across different brain regions is crucial for higher intellectual performance. Additionally, the study found that white matter organization, particularly in the cingulum tract, is positively associated with IQ, further supporting the role of both structural and functional connectivity in intelligence. The study underscores the complex interplay between brain network organization and cognitive performance, emphasizing the importance of efficient global communication in the brain for intellectual abilities.