132 CARNEGIE INSTITUTION OF WASHINGTON. 



HEREDITY IN MAN. 



As was the case last year, the Director's main line of research has been 

 the analysis of data aflforded by the Eugenics Record Office as to the 

 inheritance of human traits. 



Through the generosity of ]\Irs. E. H. Harriman and the organization 

 of the Eugenics Record Office, it has been possible to undertake a study 

 of the well-known "Jukes" family from the time of Dugdale's work to 

 the present — 40 years later. The investigation was intrusted to Dr. 

 Arthur H. Estabrook. Dr. Estabrook's results have been issued as 

 Publication No. 240 of the Carnegie Institution of Washington. The 

 main conclusions of this paper are : 



"On the whole, the later descendants of the Jukes, in Connecticut, in New 

 Jersey, even in Minnesota, still show the same feeble-mindedness, indolence, 

 licentiousness, and dishonesty; even when not handicapped by the associa- 

 tions of their bad family name and despite the fact of being surrounded by 

 better social conditions. This is because, wherever they go, they tend to 

 marry persons like themselves. On the other hand, the dispersion has led 

 some of these descendants to marry into better stocks, and this is improving 

 the quality of the germ-plasm. 



"Not merely institutional care, nor better community environment, will 

 cause good social reactions in persons who are feeble-minded or feebly in- 

 hibited, although, on the other hand, better stimuli will secure better reactions 

 from weak stock than will poor stimuli." 



The whole study will, it is thought, bring home to those interested in 

 social progress the grave importance of the constitutional or hereditary 

 factor in detennining behavior. 



The Du'ector has been engaged during the year in a study of heredity 

 of human stature, a classical topic of research which offers almost 

 insuperable obstacles to a satisfactory solution in terms of modern 

 genetic theory. To see if various segments of stature, such as head and 

 neck, trunk, thigh, and foreleg, are separately and independently 

 inheritable the Director measured personally two generations in scores 

 of famihes, chiefly on Long Island, but also in Lexington, Kentucky. 

 The results are being prepared for publication. 



The studies of the Director on the inheritance of elements of human 

 behavior are being synthesized in an analysis of the life-activities and 

 output of effective men. This topic demands extensive reading and 

 analysis of biographies and family histories in order to detennine the 

 distribution in the family of the significant traits. 



HEREDITY IN SHEEP AND POULTRY. 



The experiments on heredity of twin-production and multi-nippled 

 condition have been continued. In the spring, from 10 ewes, 22 lambs 

 were born, all multi-nippled. As the ewes have 4 functional mam- 

 mary glands, they were successful in feeding and rearing their young. 



