One of the earliest psychology societies was La Société de Psychologie Physiologique in France, which lasted 1885–1893. The first meeting of the International Congress of Psychology took place in Paris, in August 1889, amidst the World's Fair celebrating the centennial of the French Revolution. William James was one of three Americans among the four hundred attendees. The American Psychological Association was founded soon after, in 1892. The International Congress continued to be held, at different locations in Europe, with wider international participation. The Sixth Congress, Geneva 1909, included presentations in Russian, Chinese, and Japanese, as well as Esperanto . After a hiatus for World War I, the Seventh Congress met in Oxford, with substantially greater participation from the war-victorious Anglo-Americans. In 1929, the Congress took place at Yale University in New Haven, Connecticut, attended by hundreds of members of the American Psychological Association  Tokyo Imperial University led the way in bringing the new psychology to the East, and from Japan these ideas diffused into China.  
A question that may be asked about an adaptation is whether it is generally obligate (relatively robust in the face of typical environmental variation) or facultative (sensitive to typical environmental variation).  The sweet taste of sugar and the pain of hitting one's knee against concrete are the result of fairly obligate psychological adaptations; typical environmental variability during development does not much affect their operation. By contrast, facultative adaptations are somewhat like "if-then" statements. For example, adult attachment style seems particularly sensitive to early childhood experiences. As adults, the propensity to develop close, trusting bonds with others is dependent on whether early childhood caregivers could be trusted to provide reliable assistance and attention. The adaptation for skin to tan is conditional to exposure to sunlight; this is an example of another facultative adaptation. When a psychological adaptation is facultative, evolutionary psychologists concern themselves with how developmental and environmental inputs influence the expression of the adaptation.