which group most directly influenced both the Maya and Aztec

The group that most directly influenced both the Maya and Aztec civilizations is the Olmec civilization. The Olmecs were a Pre-Columbian civilization that thrived in the region of modern-day Mexico from approximately 1500 BCE to 400 BCE. They are regarded as one of the earliest complex societies in Mesoamerica and are considered the "mother culture" of the region.

To understand how the Olmecs influenced the Maya and Aztec civilizations, we can look at their cultural, artistic, and architectural legacy. The Olmecs developed a sophisticated civilization with advanced agricultural techniques, trade networks, and complex social and political structures. They constructed monumental architecture, including pyramids and ceremonial centers, which had a lasting impact on the architectural styles of later Mesoamerican civilizations.

The artistic style of the Olmecs also influenced the Maya and Aztec civilizations. The Olmecs are particularly known for their colossal stone heads, which depicted their rulers and displayed a distinctive artistic style characterized by wide, flat facial features and elaborate headgear. This style continued to be emulated by subsequent civilizations in Mesoamerica.

Furthermore, the Olmecs had a significant cultural influence on the Maya and Aztec societies through their religious beliefs and practices. The Olmecs worshiped a pantheon of gods and performed rituals involving bloodletting and offerings, which later became central elements of Maya and Aztec religious practices.

So, to summarize, the Olmec civilization, with its cultural, artistic, and architectural achievements, directly influenced both the Maya and Aztec civilizations, shaping their development and leaving a lasting impact on their respective cultures.