“Emergenesis: Genetic Traits That May Not Run in Families § Genius”, 1992 (; similar):
[Further discussion of “emergenesis” and relationship to genius: why are geniuses, while sometimes clearly affiliated with entire clans, so sporadic even within those? This is difficult to explain on any environmental or simple additive genetic grounds, suggesting that it may require entire complexes of exactly aligned genes and environmental factors.]
Human genius has always been a problem for both environmentalists and hereditarians to understand (1869; 1944; 1988). There have been families of genius, of course—the Bernoullis and the Baths, the Darwins and the Huxleys, the musical Marsalis family—but it is the solitary genius, rising like a great oak in a forest of scrub and bramble, who challenges our understanding. Carl Friedrich Gauss, ranked with Archimedes and Newton as one of the “princes of mathematics”, had uneducated parents. His mother was illiterate, yet the boy had taught himself to read and to do simple arithmetic by the time he was 3 years old (1981).
…Suppose that Gauss or Ramanujan had been born with a healthy MZ twin who was spirited away to be reared by some country parson in Oxfordshire. Barring cholera or other accident, is it not likely that the parson’s surname too would now be immortal? Ramanujan died young without offspring; his parents and one brother apparently were unexceptional. Although Gauss provided rich stimulation and opportunity for his six offspring (by two different and highly cultivated wives), none of them distinguished themselves.2 But if the genius of these men was prefigured in their genes, why was it never manifested elsewhere in their lineage? The answer is, we think, that genius consists of unique configurations of attributes that cannot be transmitted in half helpings.