SKIN COLOR OF MULATTOES 



Apparently Four Factors Involved— Segregation in Second Generation — Skin 



Pigment Developed After Birth No Correlation Between Color of Skin and 



Curliness of Hair in Offspring of Mulatto Marriages.' 



Charles B. Davenport 



Director, Department of Experimental Evolution (Carnegie Institution of Wash- 

 ington), Cold Spring Harbor, Long Island, New York. 



THE method of heredity in negro- 

 white crosses has long been cited 

 as a demonstration of the fail- 

 ure of modern principles of 

 heredit>- in their application to some 

 specific cases. Skin color is said to 

 show a typical blending, as in the mu- 

 latto, and it is generally assumed that 

 all of the offspring of two mulattoes 

 resemble their parents in skin color; 

 and if a mulatto be crossed with a 

 white that all of the offspring will be 

 of a shade still lighter than the mulatto 

 parent, namely, of a quadroon color. 

 The current theory also has a great 

 social importance because according to 

 it, "once a negro, always a negro;" 

 since the negro characteristics can not 

 be wholly eliminated even by successive 

 matings with white. However, as a 

 concession, certain States even in our 

 South permit the offspring of a person 

 containing one-eighth negro blood and a 

 pure white to ])ass as a white citizen and 

 to marry, legally, a white j^erson. That 

 is, after matings of a mulatto and her 

 offspring for two further generations 

 with white persons the final generation 

 may pass for white. 



In order to test the theory that hy- 

 bridization of skin color really does 

 show a typical blending and failure to 

 segregate, the author, with the assistance 

 of a trained field agent (Miss Florence 

 Danielson), has made measurements 

 upon the skin color of between 600 and 

 700 children derived from about 200 

 })airs of i)arents and also of various 

 other relatives. These studies were 

 made chiefly in the islands of Bermuda 



» This study wa.s puV)lishc(l in 1Q13 by the Carnegie Institution as publication No. 188, "Here- 

 dity of Skin Color in Negro and White Crosses." The accompanying illustrations are reproduced 

 from that monograph. 

 5S6 



and Jamaica because it was believed 

 that the investigation would meet in 

 those islands with fewer social obstacles. 

 Such social obstacles were, indeed, en- 

 countered but the restilt justified the 

 selection of the localities. The measure- 

 ment of the skin color was made by 

 the aid of a color top in which the pro- 

 portion of black, red, yellow and white 

 factors upon a circular disk may be 

 varied so that, when the top is spun, 

 any desired combination of proportions 

 of these colors may be secured. The 

 result of this investigation is clear cut, 

 namely, skin color does segregate and 

 the offspring of two strict mulatto 

 parents may have skin color ranging 

 from that of a pure white to quite dark 

 in color, like that of a West Coast 

 African negro. Segregation certainly 

 does take place. 



FACTORS ARE COMPLICATED. 



The study shows, moreover, that the 

 a])]^arent blending is due to the com- 

 ])licated nature of the factors upon which 

 negro skin color depends. After careful 

 analysis of all of the results of all of the 

 varied matings that were studied, the 

 conclusion was drawn that in the full- 

 blooded negro there arc four factors that 

 make for skin pigmentation and that 

 corresjjondingly there are five condi- 

 tions of these factors possible in the 

 skin of the descendants of mulattoes, 

 namely, no factor for black, one factor, 

 two factors, three factors, or four fac- 

 tors for black. It follows from the fact 

 of segregation also that the offsjjring of 

 two mulattoes arc much more variable 



