172 BIOLOGY OF DEATH 



Friends' Societies. It appears in the upper half of the 

 table that wherever a parent, father or mother, appears 

 with a minor son or daughter the correlation coefficients 

 are small in magnitude. In some cases they are just 

 barely significant in comparison with their probable errors 

 as for example, the correlation of father and minor 

 son, and that of mother and minor daughter. In the 

 other cases involving minors the coefficients are so small 

 as to be insignificant. On the other hand, in every case 

 of correlation between parent and adult offspring of 

 either sex, the coefficient is 6 or more times its probable 

 error, and must certainly be regarded as significant. It- 

 will further be noted that the magnitude of the coefficients 

 obtained from these Quaker records, is of the same general 

 order as was seen in the previous table based on the 

 "Peerage" and "Landed Gentry" material. 



The lower part of the table gives the results for 

 various fraternal relationships. In general the frater- 

 nal correlations are higher that the parental. The coeffi- 

 cients for minors or for minors with adults are very low 

 and in most cases not significantly different from zero. 

 In four cases namely, adult brother with minor brother ; 

 adult sister with minor sister ; adult brother with minor 

 sister; and adult sister with minor brother the coeffi- 

 cients are all negative in sign, although in no one of the 

 cases is the coefficient significant in comparison with 

 its probable error. A minus sign before a correlation 

 coefficient means that an increase in the value of 

 one of the variables is associated with a decrease 

 in the value of the other. So that these negative 

 coefficients would mean, if they were significant, that 

 the greater the age at death of an adult brother, the lower 

 the age at death of his minor brother or sister. But the 

 coefficients are actually sensibly equal to zero. Pearson 



