MENTAL CHARACTERS IN MAN 163 



(191 5) treats as a fundamental lunnan instinct, 

 which is typically inhibited in intc^llii^cnt civilised 

 adults. It appears to be a sex-linked recessive 

 monoh3'brid trait. Sons are found to be nomadic 

 only when their mothers belong to nomadic stock. 

 Daughters are nomadic only when the mother belongs 

 to such a stock and the father is also nomadic. 

 The impulse occurs frequently in families showing 

 such periodic behaviour as depression, migraine,* 

 epilepsy, and hysteria. Nomadism would appear to 

 be more widespread in the Anglo-Saxon population 

 of North America than in the resident population of 

 Britain. This is probably because emigration has 

 always been more largely of the roving types, the 

 more sedentary elements of the population preferring 

 to remain behind. This difference probably applies 

 chiefly to the labouring and agricultural classes, the 

 higher classes being able to satisfy their nomadic 

 instincts by travel. 



The relation of criminality to inheritance is often 

 debated. Obviously it cannot be a simple one. 

 Davenport (1920) classifies antisocial behaviour as 

 due to one of the following four sets of conditions : 

 (i) Ignorance of the mores (or social requirements), 

 merely through lack of opportunity to learn the 

 mores. This condition would apply partially to the 

 foreigner, or to the improperly or insufficiently taught 

 offender. (2) Ignorance of the mores through lack 

 of capacity to understand what society expects. 

 This is characteristic of the feebleminded. (3) Know- 

 ledge of the mores, accompanied by a social blindness 

 and inability to have the action controlled b}' a 

 knowledge of w^hat society expects of one, because 

 of lack of gregarious, social, or altruistic instinct. 



* A nervous affection marked by periodic headache, often 

 confined to one side of the head, and accompanied by nausea 

 and other symptoms. 



