Executive functions (EFs) are a set of cognitive processes that regulate thoughts and behaviors, and individual differences in EFs have been studied extensively. This article summarizes four key conclusions from research on individual differences in EFs. First, EFs show both unity and diversity, meaning that while different EFs are correlated, they are also separable. Second, individual differences in EFs are significantly influenced by genetic factors. Third, EFs are related to various clinically and societally important phenomena, such as behavioral disinhibition and self-regulation. Fourth, individual differences in EFs show some developmental stability, meaning that they remain relatively consistent over time. EFs include updating, shifting, and inhibition. Updating involves maintaining and updating working memory, shifting involves switching between tasks, and inhibition involves controlling impulses. These EFs are measured using various tasks, such as the letter memory task, color-shape task, and antisaccade task. Research has shown that these tasks can capture important aspects of EFs, even though they may include non-EF processes. The unity/diversity framework is a new theoretical approach that helps explain the nature of individual differences in EFs. This framework suggests that EFs can be decomposed into common components (Common EF) and specific components (e.g., updating-specific, shifting-specific). This approach allows for a more direct examination of the cognitive and biological underpinnings of EFs. Genetic studies have shown that individual differences in EFs are influenced by genetic factors. Twin studies have found that heritability estimates for EFs are relatively high, especially at the level of latent variables. This suggests that genes play a significant role in individual differences in EFs. EFs are also related to various clinically and societally important behaviors, such as behavioral disinhibition and self-regulation. Research has shown that better EF abilities are associated with fewer behavioral problems. Additionally, EFs are related to the regulation of substance use and eating behavior. Finally, individual differences in EFs show some developmental stability, meaning that they remain relatively consistent over time. Longitudinal studies have shown that EFs measured in childhood are predictive of EFs measured in adolescence. This suggests that EFs are relatively stable over time, even though they can change within individuals. Overall, the research on individual differences in EFs has provided important insights into the nature of EFs and their cognitive and biological underpinnings. These findings have important implications for both basic and applied research in psychology.Executive functions (EFs) are a set of cognitive processes that regulate thoughts and behaviors, and individual differences in EFs have been studied extensively. This article summarizes four key conclusions from research on individual differences in EFs. First, EFs show both unity and diversity, meaning that while different EFs are correlated, they are also separable. Second, individual differences in EFs are significantly influenced by genetic factors. Third, EFs are related to various clinically and societally important phenomena, such as behavioral disinhibition and self-regulation. Fourth, individual differences in EFs show some developmental stability, meaning that they remain relatively consistent over time. EFs include updating, shifting, and inhibition. Updating involves maintaining and updating working memory, shifting involves switching between tasks, and inhibition involves controlling impulses. These EFs are measured using various tasks, such as the letter memory task, color-shape task, and antisaccade task. Research has shown that these tasks can capture important aspects of EFs, even though they may include non-EF processes. The unity/diversity framework is a new theoretical approach that helps explain the nature of individual differences in EFs. This framework suggests that EFs can be decomposed into common components (Common EF) and specific components (e.g., updating-specific, shifting-specific). This approach allows for a more direct examination of the cognitive and biological underpinnings of EFs. Genetic studies have shown that individual differences in EFs are influenced by genetic factors. Twin studies have found that heritability estimates for EFs are relatively high, especially at the level of latent variables. This suggests that genes play a significant role in individual differences in EFs. EFs are also related to various clinically and societally important behaviors, such as behavioral disinhibition and self-regulation. Research has shown that better EF abilities are associated with fewer behavioral problems. Additionally, EFs are related to the regulation of substance use and eating behavior. Finally, individual differences in EFs show some developmental stability, meaning that they remain relatively consistent over time. Longitudinal studies have shown that EFs measured in childhood are predictive of EFs measured in adolescence. This suggests that EFs are relatively stable over time, even though they can change within individuals. Overall, the research on individual differences in EFs has provided important insights into the nature of EFs and their cognitive and biological underpinnings. These findings have important implications for both basic and applied research in psychology.