Racial theories Sergi's initial contribution was to oppose the use of the cephalic index to model population ancestry, arguing that over all cranial morphology was more useful. However, Sergi's major theoretical achievement was his model of human ancestry, fully articulated in his books Human Variation (Varietà umane. Principio e metodo di classificazione) and The Mediterranean Race (1901), in which he argued that the earliest European peoples arose from original populations in the Horn of Africa, and were related to Hamitic peoples. This primal "Eurafrican race" split into three main groups, the Hamites, the Mediterranean race and the north European Nordic race. Semitic people were closely related to Mediterraneans but constituted a distinct "Afroasian" group. The four great branches of the Mediterranean stock were the Libyans or Berbers, the Ligurians, the Pelasgians and the Iberians. Ancient Egyptians were considered by Sergi as a branch of the Hamitic race. According to Sergi the Mediterranean race, the "greatest race in the world", was responsible for the great civilisations of ancient times, including those of Egypt, Carthage, Greece and Rome. These Mediterranean peoples were quite distinct from the peoples of northern Europe. Sergi argued that the Mediterraneans were more creative and imaginative than other peoples, which explained their ancient cultural and intellectual achievements, but that they were by nature volatile and unstable. In his book The Decline of the Latin Nations he argued that Northern Europeans had developed stoicism, tenacity and self-discipline due to the cold climate, and so were better adapted to succeed in modern civic cultures and economies. Anti-Nordicism These theories were developed in opposition to Nordicism, the claim that the Nordic race was of pure Aryan stock and naturally superior to other Europeans. Sergi ridiculed Nordicists who claimed that the leaders of ancient Greek and Roman civilization were Germanic in origin and argued that the Germanic invasions at the end of the Roman Empire had produced "delinquency, vagabondage and ferocity". Sergi believed that the Aryans were originally "Eurasiatic" barbarians who migrated from the Hindu Kush into Europe. He argued that the Italians had originally spoken a Hamitic language until the Aryan (Indo-European) Italic language spread across the country. Some Aryan influence was detectable in Northern Italy, bu, racially speaking, Italians were unaffected by Aryan migrants. Sergi expanded on those theories in later publications. Despite his denigration of Aryans and emphasis on Mediterranean racial identity, he denied that he was motivated by