There was a struggle to keep people in the profession during the post-war years. Emphasis shifted from the altruistic war-time mentality to the financial, professional, and personal satisfaction that comes with being a therapist. To make the profession more appealing, practice was standardized, as was the curriculum. Entry and exit criteria were established, and the American Occupational Therapy Association advocated for steady employment, decent wages, and fair working conditions. Via these methods, occupational therapy sought and obtained medical legitimacy in the 1920s. The 1920s and 1930s were a time of establishing standards of education and laying the foundation of the profession and its organization. Eleanor Clarke Slagle proposed a 12-month course of training in 1922, and these standards were adopted in 1923. Educational standards were expanded to a total training time of 18-months in 1930 to place the requirements for professional entry on par with those of other professions. The first textbook was published in the United States for occupational therapy in 1947, edited by Helen S. Willard and Clare S. Spackman. The profession continued to grow and redefine itself in the 1950s. The profession also began to assess the potential for the use of trained assistants in the attempt to address the ongoing shortage of qualified therapists, and educational standards for occupational therapy assistants were implemented in 1960. The 1960s and 1970s were a time of ongoing change and growth for the profession as it struggled to incorporate new knowledge and cope with the recent and rapid growth of the profession in the previous decades. New developments in the areas of neurobehavioral research led to new conceptualizations and new treatment approaches, possibly the most groundbreaking being the sensory integrative approach developed by A. Jean Ayres.