The Serranos recognized a hierarchy of supernatural beings and spirits. Shamans conducted their ceremonies and acquired their powers through dreaming and datura-induced visions.
Autonomous lineages, the main political unit, claimed specific local territory. Larger social units included clans, headed by kikas who provided political, economic, and religious leadership. Kikas also had assistants. Each person belonged to one of two divisions, Wildcat and Coyote, each of which was composed of a number of patrilineal clans. In addition to conducting religious ceremonies, shamans also interpreted dreams and cured both by sucking out disease objects and by administering medicinal plants.
Both young men and women undertook puberty ceremonies. Waxan, the female ceremony, was public in the case of wealthy families and included dietary restrictions and instructions on how to be good wives. During Tamonin, the boys' ceremony, initiates ingested a jimsonweed (datura) drink and danced around a fire in the ceremonial house. After they experienced their visions, they learned special songs. The ceremony was followed by feasting and gift giving. A new mother and child lived in a heated pit for several days, observing food taboos. The dead were cremated, and most of their possessions were burned. A month after the death, a second burning of the remaining possessions was held, accompanied by singing and dancing. There was also an annual seven-day mourning ceremony.
Parents, unmarried daughters, married sons, and sometimes extended family members lived in circular, domed tule-mat houses built around willow frames. Most household activities took place in nearby ramadas. Other structures included granaries, semisubterranean sweat houses, and a large ceremonial house where the kika lived. Men, women, and children all sweated and bathed together.
The Serranos made fine decorated coiled basketry. They also carved petroglyphs, beginning perhaps as early as 1000 BCE, that depicted big game hunting. Pictographs, consisting of geometric designs, straight and wavy lines, and people, were painted as part of the girls' puberty ceremony as early as 1400.
The Serranos may have encountered the Spanish as early as the 1770s, but the latter exerted little influence until 1819, when they constructed a settlement in the area. Most western Serranos were removed by force to the missions between then and 1834; at that point, too few remained to carry on a traditional lifestyle. The Vanyumes, a group associated with the Serranos and possibly living just to their north, became extinct well before 1900.