This study investigates the walking behavior of pedestrian social groups and its impact on crowd dynamics. Researchers observed the motion of approximately 1500 pedestrian groups in natural conditions and found that social interactions among group members generate typical group walking patterns that influence crowd dynamics. At low density, group members tend to walk side by side, forming a line perpendicular to the walking direction. As density increases, the linear formation bends forward, turning into a V-like pattern. These spatial patterns are well described by a model based on social communication between group members. The V-like pattern facilitates social interactions but reduces flow due to its non-aerodynamic shape. When crowd density increases, group organization results from a trade-off between walking faster and facilitating social exchange. The study shows that crowd dynamics are not only determined by physical constraints but also significantly by communicative and social interactions among individuals. Empirical observations revealed that up to 70% of pedestrians in a crowd are moving in groups, with group sizes following a Poisson distribution. The average walking speed of pedestrians is clearly dependent on density, with pedestrians walking faster at low density. Additionally, pedestrian walking speeds decrease linearly with growing group size. The spatial organization of walking pedestrian groups was analyzed, revealing specific patterns of spatial group organization that change with increasing density. At low density, group members walked in a horizontal formation, while at higher density, the group formed a V-like or U-like pattern. These configurations are emergent patterns resulting from the tendency of each pedestrian to find a comfortable walking position supporting communication with other group members. A mathematical model was developed to describe the social interactions among group members, incorporating social communication and the need to maintain a certain distance from the group's center of mass. The model showed that the strength of social interactions (represented by parameter β₁) is essential to capture the dynamics of the system. When β₁ is set to 0, group members form an inverse V-like configuration, while for β₁=4, the observed forwardly directed V-like pattern is generated, which affects the overall walking speed of the crowd. The study highlights the importance of considering social interactions in future studies of pedestrian dynamics, as pedestrian groups significantly impact traffic efficiency and crowd behavior. The findings suggest that group organization is actively created and maintained to support certain functions, such as better communication. The results also indicate that as density increases, the physical constraints may prevail over social preferences, leading to a river-like following pattern. The study provides insights into the complex dynamics of human crowds and the role of social interactions in shaping pedestrian behavior.This study investigates the walking behavior of pedestrian social groups and its impact on crowd dynamics. Researchers observed the motion of approximately 1500 pedestrian groups in natural conditions and found that social interactions among group members generate typical group walking patterns that influence crowd dynamics. At low density, group members tend to walk side by side, forming a line perpendicular to the walking direction. As density increases, the linear formation bends forward, turning into a V-like pattern. These spatial patterns are well described by a model based on social communication between group members. The V-like pattern facilitates social interactions but reduces flow due to its non-aerodynamic shape. When crowd density increases, group organization results from a trade-off between walking faster and facilitating social exchange. The study shows that crowd dynamics are not only determined by physical constraints but also significantly by communicative and social interactions among individuals. Empirical observations revealed that up to 70% of pedestrians in a crowd are moving in groups, with group sizes following a Poisson distribution. The average walking speed of pedestrians is clearly dependent on density, with pedestrians walking faster at low density. Additionally, pedestrian walking speeds decrease linearly with growing group size. The spatial organization of walking pedestrian groups was analyzed, revealing specific patterns of spatial group organization that change with increasing density. At low density, group members walked in a horizontal formation, while at higher density, the group formed a V-like or U-like pattern. These configurations are emergent patterns resulting from the tendency of each pedestrian to find a comfortable walking position supporting communication with other group members. A mathematical model was developed to describe the social interactions among group members, incorporating social communication and the need to maintain a certain distance from the group's center of mass. The model showed that the strength of social interactions (represented by parameter β₁) is essential to capture the dynamics of the system. When β₁ is set to 0, group members form an inverse V-like configuration, while for β₁=4, the observed forwardly directed V-like pattern is generated, which affects the overall walking speed of the crowd. The study highlights the importance of considering social interactions in future studies of pedestrian dynamics, as pedestrian groups significantly impact traffic efficiency and crowd behavior. The findings suggest that group organization is actively created and maintained to support certain functions, such as better communication. The results also indicate that as density increases, the physical constraints may prevail over social preferences, leading to a river-like following pattern. The study provides insights into the complex dynamics of human crowds and the role of social interactions in shaping pedestrian behavior.