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date: 28 February 2020

Ladd-Franklin, Christinefree

(01 December 1847–05 March 1930)
  • Laurel Furumoto

Ladd-Franklin, Christine (01 December 1847–05 March 1930), psychologist and logician, was born in Windsor, Connecticut, the daughter of Eliphalet Ladd, a farmer and merchant, and Augusta Niles. Soon after the death of her mother, when Ladd-Franklin was twelve, she went to live with her paternal grandmother in Portsmouth, New Hampshire. She graduated from Welshing Academy, a coeducational institution in Wilbraham, Massachusetts, in 1865 as valedictorian of her class. When, because of financial reverses, her father could not afford to send her to Vassar College, a maternal aunt provided the necessary funds. At Vassar she studied astronomy with Maria Mitchell, the premier nineteenth-century American woman scientist, and after two years in residence (1866–1867, 1868–1869) was awarded an A.B. in 1869. For the next nine years, she taught high school science and mathematics in several different localities, while at the same time she submitted mathematical problems and solutions to the Educational Times of London.

In 1878 Ladd-Franklin applied for admission to the recently established Johns Hopkins University, the first institution in the United States to be devoted primarily to research and graduate instruction. Although Johns Hopkins was officially closed to women at that time, Ladd-Franklin’s contributions to the Educational Times gained her an entrée to the university. Her name was recognized by James J. Sylvester, an Englishman and professor of mathematics at Johns Hopkins who urged that she be accepted. In her first year at the school, she was allowed to attend only Sylvester’s classes. In subsequent years this restriction was lifted, and for each of the next three academic years she was even awarded a fellow’s stipend, but not the title (in order to avoid setting a precedent for awarding fellowships to women).

By 1882 Ladd-Franklin had completed all of the requirements for a doctorate in mathematics and logic, but it was not awarded because Johns Hopkins was still unwilling at that time to grant degrees to women. Not until 1926, as part of its fiftieth anniversary celebration, did Johns Hopkins award Ladd-Franklin the Ph.D. Her dissertation is credited with having contributed to the development of the field of symbolic logic, also known as Boolean logic, which reduced Aristotelian logic to an algebraic calculus. “On the Algebra of Logic” was published in 1883 as part of a collection of works by students of her adviser, Charles Sanders Peirce, entitled Studies in Logic by Members of the Johns Hopkins University. In 1882 she married one of her former mathematics professors, Fabian Franklin; they had two children.

By 1887 Ladd-Franklin had developed an interest in theories of vision and was beginning to publish the results of her research on this topic. Her first paper was a report of her investigation of the nature of the horopter, a mathematical question concerned with binocular vision.

During Fabian Franklin’s 1891–1892 sabbatical year, the couple traveled to Germany, where Ladd-Franklin studied color vision. She spent the first half of the year in Göttingen in the laboratory of psychologist G. E. Müller and the second half in the laboratory of Hermann von Helmholtz, physicist and physiologist, working under the direction of physicist Arthur König. By the summer of 1892 Ladd-Franklin had come up with her own theory of color vision, which she claimed was able to account for all of the phenomena explained by the two major rival theories of that day. The Hering theory, endorsed by Müller, proposed three opponent color processes in the retina—white-black, yellow-blue, and red-green—and the Young-Helmholtz theory, supported by König, maintained that there were three modes of color excitation in the retina: red, green, and violet. Building on these two theories, which she argued were not contradictory but rather pertained to different stages of the visual process, Ladd-Franklin advanced her own, original contribution: the idea of the evolutionary development of color sensation from achromatic (black and white) to dichromatic (yellow and blue) to tetrachromatic (yellow, blue, red, and green). Although her theory received considerable attention and support during her lifetime, it was eventually superseded by more encompassing theories that included neural mechanisms beyond the retina.

Ladd-Franklin first announced her theory in a paper presented at the Second International Congress of Psychology in London in August 1892. She spent the rest of her life promoting it. In the decade following the invention of her color theory, she published prolifically on the subject of vision and was an associate editor and contributor on that topic for the second volume of the Dictionary of Philosophy and Psychology (1902). By the advent of the twentieth century, she had become an internationally recognized authority on vision.

Promoted to professor of mathematics in 1892, Fabian Franklin resigned from Johns Hopkins in 1895 to become editor of the Baltimore News. In 1909 he accepted a position as associate editor of the New York Evening Post, and the family moved to New York City, where the couple resided for the rest of their lives. Although Ladd-Franklin never held a regular academic appointment, she taught courses at Johns Hopkins on color vision and on logic between 1904 and 1909, and from 1914 to 1929 she had an appointment without salary at Columbia University, where she continued to offer courses on these topics. Between 1912 and 1914 she presented a lecture series on color theory at Columbia, Clark, and Harvard universities and at the University of Chicago. A collection of her articles on color vision, which had originally appeared between 1892 and 1926, were published as Colour and Colour Theories (1929).

From her adolescence onward, Ladd-Franklin was a militant supporter of women’s rights who championed such causes as equal access to education and the professions and woman suffrage. Beginning in 1912, and for several years thereafter, she assailed Edward Bradford Titchener, an eminent Cornell University psychologist, for excluding women from the elite society he had established in 1904, known as “the Experimentalists.” In 1914, when the annual meeting of this group was to be held at Columbia University, as Ladd-Franklin put it in a letter to Titchener, “at my very door,” she accused him of holding to a “mediaeval attitude” by refusing to include women psychologists, an attitude that she decried as being “so unconscientious, so immoral,—worse than that—so unscientific!” (Scarborough and Furumoto, p. 126).

Ladd-Franklin lost the distinction of being the first American woman to receive a Ph.D. in mathematics to Winifred Haring Edgerton (who was awarded the degree by Columbia University in 1886) despite having completed all of the requirements for a doctorate in mathematics and logic by 1882. Her major scientific contribution, however, came in the field of psychology, in which, in the 1906 edition of James McKeen Cattell’s American Men of Science, she was listed as fifteenth among the fifty psychologists judged to be the most eminent in the field. During her lifetime, her theory of color sensation came to rank in importance directly behind the Young-Helmholtz and Hering theories, although mention of the Ladd-Franklin theory can rarely be found in late twentieth-century discussions of the history of color theories. She died in New York City.


An extensive collection, largely unprocessed, of Ladd-Franklin’s papers is in the Rare Book and Manuscript Library of Columbia University. For discussions of Ladd-Franklin’s work in logic and mathematics see Judy Green, “Christine Ladd-Franklin (1847–1930),” in Women of Mathematics: A Biobibliographic Sourcebook, ed. Louise S. Grinstein and Paul J. Campbell (1987), and Green and Jeanne Laduke, “Contributors to American Mathematics: An Overview and Selection,” in Women of Science: Righting the Record, ed. G. Kass-Simon and Patricia Farnes (1990). See Thomas C. Cadwallader and Joyce V. Cadwallader, “Christine Ladd-Franklin (1847–1930),” in Women in Psychology: A Bio-Bibliographic Sourcebook, ed. Agnes N. O’Connell and Nancy Felipe Russo (1990), for her career and contributions to psychology; Laurel Furumoto, “Joining Separate Spheres—Christine Ladd-Franklin, Woman-Scientist (1847–1930),” American Psychologist 47 (1992): 175–82, on gender issues in her life and career; and Elizabeth Scarborough and Furumoto, Untold Lives: The First Generation of American Women Psychologists (1987), for an account of her reaction to a policy of exclusion of women psychologists by their male colleagues.