Psychology as a formal discipline is now well over 100 years old, having been recognised officially with the establishment of Wundt's experimental laboratory in Leipzig in 1879. The centennial was celebrated in 1980 at the International Congress of Psychology in Leipzig in honor of this great event in the history of psychology. The international movements in psychology are not far behind in age. From these movements three major general international psychological associations have sprung up and are still flourishing. They are also still sponsoring quadrenniel congresses or annual conventions, although until 1976 when the International Congress of Psychology was held in Paris, this was not always de case. These three international organisations are:

The International Association of Applied Psychology (IAAP) or Association Internationale de Psychologie Appliquee (AIPA) is the oldest international association of psychologists. It was founded in 1920 as the International Association of Psychotechnology or Association International de Psychotechnique. The association was known by this name until it was changed to the current name in 1955 during the tenure (1953-58) of Clifford Frisby, who was the first non-French speaking president. Frisby, incidentally, was also a nonpsychologist; he was a business man and is the only such president to have served in that office in IAAP. He was the head of the once-great National Institute for Industrial Psychology in Great Britain which, in the 1920s, led the world in industrial psychology and vocational guidance.

The Association is responsible for organising the  International Congress of Applied Psychology. The past congresses of IAAP, the city, country and year win which each was held and the name of the organizer of the congress are as follows:

I Geneva, Switzerland 1920 E. Claparède
II Barcelona, Spain 1921 E. Claparède
III Milan, Italy 1922 G. Ferrari
IV Paris, France 1927 E. Toulouse
V Utrecht, Holland 1928 N. Roels
VI Barcelona, Spain 1930 E. Mira i López
VII Moscow, USSR 1931 N. Spielrein
VIII Prague, Csechoslovakia 1934 R. Seracky
IX Bern, Switzerland 1949 H. Pieron
X Göteborg, Sweden 1951 J. Elmgren
XI Paris, France 1953 F. Bonnardel
XII London, UK 1955 C. Frisby
XIII Rome, Italy 1958 T. Canstrelli
XIV Copenhagen, Denmark 1961 R. Tranekjaer
XV Ljubljana, Yugoslavia 1964 Z. Bujas
XVI Amsterdam, The Netherlands 1968 N. Wijngaarden
XVII Liège, Belgium 1971 R. Piret
XVIII Montreal, Canada 1974 L. Dorais
XIX Munich, Germany 1978 R. Amthauer
XX Edinburgh, UK 1982 G. Randell
XXI Jerusalem, Israel 1986 Y. Amir
XXII Kyoto, Japan 1990 J. Misumi
XXIII Madrid, Spain 1994 J.M. Prieto
XXIV San Francisco, US 1998 J. Matarazzo
XXV Singapore 2002 E. Nair
XXVI Athens, Greece 2006 J. Georgas & M. Manthouli
XXVII Melbourne, Australia 2010 P. Martin 
XXVIII Paris, France 2014 C. Roland-Levy

Beginning with the IUPsyS Congress in Paris in 1976, IAAP Congresses started to be organized on a four year cycle.

The IAAP was organised primarily to establish contact and communication among psychologists on an international scale. For the first 50 years of its existence, the Association, although international in nature and in scope, was dominated by European psychology and psychologists. This fact is emphasized by noting who its principal officers were, where its congresses were held, and the nationalities of the organizers of those international meetings. While many Americans and other non-Europeans were members of the Association in those early days, they did not assume major leadership roles. Perhaps much of this was due to the earlier emphasis in psychology outside of Europe (particularly U.K. and France) on experimental and theoretical psychology rather than clinical, counseling and industrial psychology.

All of this seems to have changed with the Montreal Congress, the first to be held outside of Europe, and this trend has continued after congresses held in Kyoto: ICAP move from continent to continent.