Francis Galton reported in 1874 that the first born children in families tend to achieve higher “eminence” that later born children. Since that time, many other studies have been conducted to test that finding, with mixed results. The AP reports that two Norwegian researchers, Petter Kristensen and Tor Bjerkedal, have just found that the oldest boy in the family has, on average, a higher IQ than younger boys. They found further, that the effect does not seem to be the result of being first born, per se, but of having the highest “social rank” in the family. Second born boys raised in families in which the first born boy died in infancy have IQs nearly as high as first borns. Girls were not included in the analysis. Kristensen and Bjerkedal’s article appears in this week’s issue of the journal Science.

This finding will be of interest to historians of psychology because the finding that firstborns tend to achieve higher “eminence” in life was reported by Francis Galton.

See also, from Classics in the History of Psychology:

• Galton, F.  (1865).  Hereditary talent and character.  Macmillan’s Magazine, 12, 157-166, 318-327.
• Galton, F.  (1875).  History of twins.  Inquiries into Human Faculty and its Development, 155-173.
• Galton, F.  (1880).  Statistics of mental imagery.  Mind, 5, 301-318.

• Wozniak, R. H.  (1999).  Introduction to Hereditary Genius.  Classics in Psychology, 1855-1914: Historical Essays.  Bristol, UK: Thoemmes Press.