Food storage becomes important, as does more efficient food processing in the form of manos and metates. Hunting remains important, as does shellfish collection on the coasts. By at least 1700 BC, there is evidence for sophisticated pottery decoration in the Barra phase of coastal Chiapas. By 1600 BC, large houses, mica mirrors, and fancy figurines suggest the emergence of differences in wealth and social status. These provide the foundation for Olmec culture, which begins to flourish around 1150 BC on the Gulf Coast of Mexico.
Olmec culture represents the rise of chiefdom-level societies.
It is characterized by elaborate stone sculpture, massive building projects, highly crafted artifacts of jade and other precious materials, and a distinctive art style that indicates the development of a powerful religious ideology. The most important Early Formative Olmec site is San Lorenzo. The trend towards political centralization that began in the Early Formative period continues, along with the other traits that accompany increasing social complexity. Cerros grow in size and importance. Trade in valuable minerals, such as jade and obsidian, increases.