The phenomenon was first noticed in 1883 by Carl Düsing of the University of Jena, who suggested that it was a natural regulation of the status quo. Writing in 1899, an Australian physician, Arthur Davenport, used Düsing's findings to hypothesize that the cause was the difference between the comparative ill-health of the returning troops compared to the good health of their partners.[3] Research published in 1954 by Brian MacMahon and Thomas F. Pugh showed that the sex ratio of white live-births in the United States had shown a marked increase in favor of boys between 1945 and 1947, with a peak in 1946.[4] In 2007, Satoshi Kanazawa published a paper theorizing that the effect was due to "the fact that taller soldiers are more likely to survive battle and that taller parents are more likely to have sons".