At the request of Alexander Graham Bell, founder and director of the Genealogical Record Office, Paul Popenoe made an examination and report on these records in the fall of 1916. Thanks are due to Dr. Bell for permitting the use in this chapter of two portions of the investigation.

Beeton, Mary, and Karl Pearson, Biometrika I, p. 60. The actual correlation varies with the age and sex: the following are the results: Collateral Inheritance

Elder adult brother and younger adult brother.2290 ± .0194 Adult brother and adult brother.2853 ± .0196 Minor brother and minor brother.1026 ± .0294 Adult brother and minor brother-.0262 ± .0246 Elder adult sister and younger adult sister.3464 ± .0183 Adult sister and adult sister.3322 ± .0185 Minor sister and minor sister.1748 ± .0307 Adult sister and minor sister-.0260 ± .0291 Adult brother and adult sister.2319 ± .0145 Minor brother and minor sister.1435 ± .0251 Adult brother and minor sister-.0062 ± .0349 Adult sister and minor brother-.0274 ± .0238

The method used is the ingenious one devised by J. Arthur Harris (Biometrika IX, p. 461). The probable error is based on n=100.