120 
GENETICS: C B. DAVENPORT 
THE FEEBLY INHIBITED, II. NOMADISM OR THE WANDERING 
IMPULSE, WITH SPECIAL REFERENCE TO HEREDITY 
By C. B. Davenport 
STATION FOR EXPERIMENTAL EVOLUTION, CARNEGIE INSTITUTION OF WASHINGTON 
Presented to the Academy, January 12, 1915 
Some persons are always satisfied to remain at home and dislike the 
thought of traveling; at another extreme are the tramps and nomadic 
gypsies; at still another extreme are those who, capable of steady and 
effective work, periodically, often in a more or less dazed condition, run 
away from their homes. The term nomadism is here adopted for this 
trait in all of its varied manifestations, the racial connotation of the 
term being advantageous rather than otherwise. 
Nomadism has been widely studied by psychiatrists who have seen 
in the various periodic disorders with which it is often associated the 
causes of the different forms that it takes. Thus are distinguished de- 
mented, melancholic, epileptic, hysteric and other ''fuges." The present 
study starts with the inquiry: Are the similar symptoms that are asso- 
ciated with such different mental states wholly independent, or have 
they a common cause? 
A tendency to wander in some degree belongs to all locomotor ani- 
mals. That such a tendency is a fundamental instinct in man also is 
indicated by four lines of evidence: (1) that the anthropoid apes (rep- 
resenting the primate stock from which man sprang) are nomads; (2) 
that primitive peoples (Fugeians, Australians, Bushmen, Hottentots) 
are nomads and this trait is widespread among other, less primitive, 
tribes; (3) that the tendency to wander is nearly universal among young 
children who have only recently learned to walk; (4) and that, at adol- 
escence, the instinct (no doubt associated with the mating impulses) 
becomes keen again. 
To get further light on nomadism one hundred family histories, de- 
posited at the Eugenics Record Office, have been analyzed and tabulated 
according to the nature of the matings. The results of this tabulation 
is given on the following page. 
This table shows that far more males than females are nomadic, 171 
males to 15 females. This suggests the hypothesis that nomadism is 
a sex-Unked trait. If this hypothesis be true, in a mating of a normal 
man and a woman who, though normal, comes of nomadic stock, half 
of the sons and none of the daughters are nomadic. Combining matings 
1, 6, 7, and 8, which are the matings in question, we get the following 
