The internal brand of the scarlet

How, then, shall the "bad" form of wanderlust, defined as a compulsion to flee from responsibility, be distinguished from the meritorious sense of bravery and adventure - leading to "good" wanderlust - that motivated our early (largely northern European) immigrants to colonize and subdue the frontier. In his 1911 book, Davenport had warmly praised as "the enterprising restlessness of the early settlers . . . the ambitious search for better conditions. The abandoned farms of New England point to the trait in our blood that entices us to move on to reap a possible advantage elsewhere."

In a feeble attempt to put false labels on segments of complex continua, Davenport identified the "bad" form as "nomadism," defined as an inability to inhibit the urge we all occasionally feel to flee from our duties, but that decent folks suppress. Nomads are society's tramps, bums, hoboes, and gypsies - "those who, while capable of steady and effective work, at more or less regular periods run away from the place where their duties lie and travel considerable distances."

Having defined his quarry (albeit in a fatally subjective way), Davenport then required two further arguments to make his favored link of a "bad" trait to a single gene that eugenics might labor to breed down and out: he needed to prove the hereditary basis and then to find the "gene" for nomadism.

His arguments for a genetic basis must be judged as astonishingly weak, even by the standards of his generation. He simply argued, based on four dubious analogies, that features akin to nomadism emerge whenever situations veer toward "raw" nature (where genetics must rule) and away from environmental refinements of modern human society. Nomadism must be genetic because analogous features appear as "the wandering instinct in great apes," among "primitive peoples," in children (then regarded as akin to primitives under the false view that ontogeny recapitulates phylogeny), and in adolescents (in whom raw instinct temporarily overwhelms social inhibition in the Sturm und Drang of growing up). The argument about "primitive" people seems particularly weak since a propensity for wandering might be regarded as well suited to a lifestyle based on hunting mobile game, rather than identified as a mark of inadequate genetic constitution (or any kind of genetic constitution at all). But Davenport, reversing the probable route of cause and effect, would not be daunted:

If we regard the Fuegians, Australians, Bushmen and Hottentots as the most primitive men, then we may say that primitive man is nomadic. . . . It is frequently assumed that they are nomadic because they hunt, but it is more probable that their nomadic instincts force them to hunting rather than agriculture for a livelihood.

Davenport then pursues his second claim - nomadism as the product of a single gene - by tracing pedigrees stored in his Eugenics Record Office. On the subjective criterion of impressions recorded by fieldworkers, or written descriptions of amateur informants, Davenport marked all nomads in his table with a scarlet W for Wanderlust, the common German term for an urge to roam). He then examined the distribution of Ws through families and generations to reach one of the most peculiar and improbable conclusions ever advanced in a famous study: nomadism, he argued, is caused by a single gene, a sex-linked recessive located on what would later be identified as the female chromosome.