He was awarded the Green Fellowship in Mental Science (named after his future father-in-law, the head of the Princeton Theological Seminary) and used it to study in Germany with Wilhelm Wundt at Leipzig and with Friedrich Paulsen at Berlin during the following year.
Ribot's work traced the origins of psychology from Immanuel Kant through Johann Friedrich Herbart, Gustav Theodor Fechner, Hermann Lotze to Wundt.
His creation of a laboratory of experimental psychology at Toronto (which he claimed was the first in the British Empire) coincided with the birth of his daughters Helen (1889) and Elizabeth (1891) which inspired the quantitative and experimental research on infant development that was to make such a vivid impression on Jean Piaget and Lawrence Kohlberg through Baldwin's Mental Development in the Child and the Race: Methods and Processes (1894) dedicated to the subject.
During this creative phase Baldwin traveled to France (1892) to visit the important psychologists Jean-Martin Charcot (at the Salpêtrière), Hippolyte Bernheim (at Nancy), and Pierre Janet.
In his Habit and Instinct (1896) he phrased a comparable version of the theory, as he did in an address to a session of the New York Academy of Sciences (February 1896) in the presence of Baldwin.
(In the light of the foregoing, the deafening silence with which J. M. Baldwin was later treated in Oxford publications on the mind may well come to be regarded as one of the significant omissions in the history of ideas for the 20th century.
This book introduced the concept that knowledge grows through childhood in a series of distinct stages that involve interaction between innate abilities and environmental feedback, a proposal that was taken back by Piaget.
Baldwin's residence in France resulted in his pointing out the urgency of American non-neutral support for his new hosts on the French battlefields of World War I.
He published American Neutrality, Its Cause and Cure (1916) for the purpose, and when in 1916 he survived a German torpedo attack on the Sussex in the English Channel – on the return trip from a visit to William Osler at Oxford – his open telegram to the president of the United States on the affair became frontpage news (New York Times).
With the entry of America in the war (1917) he helped to organize the Paris branch of the American Navy League, acting as its Chairman till 1922.
The idea of organic selection came from the interpretation of the observable data in Baldwin's experimental study of infant reaching and its role in mental development.
In further stages of development – the ones most critical to an understanding of the evolution of mind – this was graphically illustrated in the child's efforts to draw and learning to write.
(Spinoza) (Wozniak, 2001) It is the communication of this insight into the practice-related nature of dynamogenic development, above all its integration as a creative factor in the fabric of society, that helped the students of Baldwin to understand what was left of Lamarck's signature.
Singularly illustrated by Gregory Bateson in Mind and Nature (1979) and reintegrated in contemporary studies by Terrence Deacon (The Symbolic Species: The co-evolution of language and the human brain, 1997) and other scholars of biosemiotics.
In the human species the faculty of niche building is favored by a practical intelligence able to design the circumstances that will put its vital acquirements out of harm's way in terms of (linearly predicted) natural selection.
Baldwin proposed, against the neo-Lamarckians of his day (most notably Edward Drinker Cope), that there is a mechanism whereby epigenetic factors come to shape the congenital endowment as much as – or more than – natural selection pressures.
Few people did more than Robert Wozniak, Professor of Psychology at Bryn Mawr College, for the rediscovery of the significance of James Mark Baldwin in the history of ideas.