The society of the multiples is borrowed from history; many cultures have gone through periods when great families divided society among themselves and people needed to ally themselves with one family or another if they hoped to survive. Italy during the Renaissance, China during the Three Kingdoms era, medieval Japan, and California when it was a part of Mexico are examples. The culture of the moon in Heads closely resembles that of Florence, Italy, during the Renaissance, when the dominant commercial families and the government focused on maintaining the community's economic prosperity. Scientific research on the moon is justified primarily by its potential to enhance a family's business; the only greater claim on family money is that of blood relations. William, who is not a blood relation, receives research money mostly because of the pleading of Rho and Mickey, Sandovals by birth, and Mickey receives his...