Why did canine teeth reduce so much in size from earlier to later hominids?

Canine teeth in hominids reduced in size primarily due to changes in diet and social behavior. As early hominids transitioned from a primarily raw, plant-based diet to one that included cooked foods and a greater emphasis on social cooperation, the need for large canines for fighting and display diminished. Additionally, smaller canines facilitated more efficient chewing and processing of softer foods. This evolutionary trend reflects adaptations to a more complex social structure and dietary habits.