Ladd was a vocal advocate for Japanese colonialism, including its colonization of Korea, and described Korean people as primitive and uncivilized.

[2][3][4][5][6][7] He was a grandson of Jesse Ladd and Ruby Brewster,[8] who were among the original pioneers in Madison, Lake County, Ohio.

His constant studies, however, seemed to turn his steps naturally toward a higher institution of learning, with the result that in 1866 he went to the Andover Theological Seminary.

[13] The series of lectures he delivered in Japan revolutionized its educational methods;[14] In 1899, Emperor Meiji conferred the Order of the Rising Sun, Gold Rays with Neck Ribbon, which represents the third highest of eight classes associated with the award.

Trumbull was again honored in 1907, this time with the Order of the Rising Sun, Gold and Silver Star, which represents the second highest of eight classes.

In 1887, he published Elements of Physiological Psychology,[12] the first American textbook to include a substantial amount of information on the new experimental form of the discipline.

[17] She was the daughter of Ellen Ryne and John C. Tallman, a well-known banker and business man of Bridgeport, Ohio.

The remaining ashes were interred under a monument of the rising sun in Grove Street Cemetery, New Haven, Connecticut.

[15][23][24] Case Western Reserve University conferred his name on its post of 'Distinguished Professor of Psychology', to which George Albee was appointed in 1958.