No. 447-] NOTES AND LITERATURE. 



229 



be told that of the progeny of such eminent people the younger sons 

 are more likely to be eminent than the older sons ; or conversely, 

 that eminent men, in general, particularly when not sons of eminent 



To prove the thesis stated in the last paragraph it would be 

 necessary first of all to find the average age a large random sample 

 of mothers and of fathers of a given race and time at the birth 

 of all their children and then to show that eminent people (using as 

 a measure of eminence some arbitrary standard such as the average 

 number of lines in the biographical descriptions in a number of 

 encyclopedias) were born of parents clearly older than the average 

 of parents of that race and time. But even this would not be wholly 

 satisfactory. It would be better to compare the average eminence of 

 the earlier and the later born of pairs of brothers. If the average 

 eminence of the later born brothers exceeded that of the earlier 

 born by several times the probable error then the greater chance of 

 eminence of younger sons , could be said to be demonstrated. But 

 even if the younger sons showed a clearly greater eminence, still we 

 could not assert that this greater eminence was due to inheritance of 

 acquired intellectual activity of the parents rather than to the possible 

 superior training of later sons.^ Now Mr. Redfield has not treated 

 his statistics of eminence in relation to birth rank with sufficient care ; 

 he is convinced of the truth of his theory ; and he uses all of the 

 art of a skillful lawyer to prove it. 



Mr. Redfield got a standard average age of Caucasian parents in 

 general from the Redfield genealogy, which indicates that 50% of 

 children are born from fathers under 33 years and mothers under 29 

 — these ages are taken as his standard although he thinks them 

 a trifle high for Caucasians in general. He compares witii tliis 

 standard the father's age of eminent men at the time of tlic ialler's 

 birth, gleaning his facts from encyclopedias, and finds many cases 

 of sons of old men. He devotes one chapter to - The Hall of 

 Fame " men. He finds among these many cases of e.xceedingly old 

 parentage. For instance when Franklin was born his father was 5 1 ; 

 and the total interval in three generations is 51 +57 + 70= 178 

 years. On the other hand the average birth rank of Eli Whitney's 

 male ancestors was 30 and for 25 Hall of Fame men the median 

 paternal birth rank is 35.5 years, not much above Redfield's standard. 



