In the early 1950s, the mathematical psychologists, excluding psychometricians, in North America could almost have been counted on the fingers of one hand, but by 1960 the number had increased more than tenfold. Some of them were periodically recruited by the Social Science Research Council to instruct in its summer institutes on mathematics for social scientists held at Stanford University, and they fell into the habit of summer migrations to the Stanford area for collaborative activities spiced by informal seminars.

In the summer of 1963, a number of these individuals, including R. C. Atkinson, R. R. Bush, W. K. Estes, R. D. Luce, and P. Suppes, began to discuss the desirability of starting a journal for publication of theoretical and mathematical articles in all areas of psychology, excluding only work that was primarily statistical or factor-analytic in character. An approach to Academic Press, represented by W. Hayward (Buck) Rogers evoked a positive response, and C. H. Coombs, W. J. McGill, and G. A. Miller were recruited to join Atkinson, Bush, Estes, and Luce on an Editorial Board. This group signed a contract with Academic Press in January, 1963, and the first issue of The Journal of Mathematical Psychology was published in January, 1964. A communication to the Board by the publisher in July, 1964 reported a total of 590 subscriptions, including 255 to personal subscribers.

Evidently encouraged by the auspicious start of the Journal, the same quartet of organizers, Atkinson, Bush, Estes, and Luce, began to consider other ways of cultivating the new specialty of mathematical psychology and settled on the need for meetings, in the mold of those of APA divisions or regional associations though smaller and more informal, to further face-to-face communication among investigators. In the late in the summer of 1968, they decided to proceed with a pilot experiment, and a meeting, organized by Walter Kintsch, with a program of contributed papers and symposia was held at Stanford in August, 1968.

The success of this meeting hit a responsive chord, and within months an Announcement and Call for Papers was circulated by a group at the University of Michigan headed by C. H. Coombs for a Mathematical Psychology Meeting to be held in Ann Arbor August 28, 29, 1969. "All interested scientists" were invited to attend and participate, setting a tradition of openness that has characterized the annual meetings that have continued down to the present.

Some participants in the Michigan meeting suggested the desirability of holding meetings in close proximity to the annual APA convention and an experiment was tried the next year with a meeting in Miami Beach; however, that effort did not arouse enthusiasm and the idea was abandoned. Annual sessions continued for a half dozen years with no formal organization, mailing lists being handed on from one ad hoc host group to the next.

During this period, an arrangement had been in effect with Academic Press, the publisher of the Journal of Mathematical Psychology, whereby a self-selected and self-perpetuating group of senior mathematical psychologists would constitute the Editorial Board of the Journal. At the 1976 meeting of the Board, it was decided that a formal organization of a Society for Mathematical Psychology was desirable, partly in order to enable more effective interaction with the publisher of the Journal. An organizing committee comprising W. H. Batchelder, W. K. Estes, B. F. Green, and R. D. Luce drafted bylaws and proceeded with formal incorporation as Society for Mathematical Psychology, Inc. in the state of Illinois in 1977 with Brown Grier as secretary-treasurer and the Editorial Board of the Journal as the charter executive committee. Henceforth, members of the Editorial Board would be selected by the Society's executive committee. The incorporation was allowed to lapse about 1985 but was revived in 1999 with reincorporation in the state of Utah through the efforts of the present secretary-treasurer, Thaddeus M. Cowan.

An adequate supply of academically based mathematical psychologists has proved willing to host meetings at Canadian and American universities: meetings have been hosted twice each by Brown, Indiana, Michigan, Princeton, Stanford, and UC Irvine; and once each by UC Berkeley, Chicago, Colorado, Harvard, UCLA, McMaster, Montreal, New York U, Northwestern, North Carolina, Oklahoma, Purdue, Queens, Rockefeller, UC Santa Barbara, UC Santa Cruz, Toronto, Vanderbilt, Washington, and Wisconsin.

- W. K. Estes, February 2002