James Ernest Strachan was born on 20 April 1883 in Dunedin, New Zealand. He was the son of James Cochrane Strachan, a tailor, and his wife, Helen Moir. Nothing is known of his early life, but at the age of 15 he became a pupil-teacher, and entered Dunedin Training College in 1903. Strachan also took classes at the University of Otago, graduating MA with honours in mental science in 1905. From 1906 to 1910 he was an assistant master in the secondary department of Lawrence District High School, and from 1911 to 1917 science master at Gore High School. In 1917 Strachan was appointed principal of Rangiora High School, from where he was able to complete a BSc at Canterbury College in 1921. While at Lawrence he had married Mary Irene Chalmers on 2 September 1914; they were to have one daughter.
On taking up his appointment at Rangiora, Strachan immediately began introducing reforms to the school's curriculum and organisation, aimed at creating a self-contained and self-governing community of learners. Strachan believed that the school should reflect the community in which it was located, and that a curriculum composed solely of professional subjects disadvantaged pupils not academically inclined. He gave more emphasis to existing courses in agriculture, home science and commerce to supplement the traditional professional courses. In 1926 he introduced his 'organic curriculum', which included a central core of science, technology, fine arts and sociology. It was, in part, intended to inculcate social skills such as critical thinking and citizenship.
Strachan favoured collective and co-operative behaviour over competitiveness. The prefect system was abolished and the school run by a council which included student representatives. Corporal punishment was replaced by an emphasis on self-discipline. In 1930 the prize system was abolished.
Strachan's innovations inevitably encountered opposition. Working-class parents and small farmers, who often required their children to become wage-earners as soon as possible, objected to the encouragement given them to remain at school. For other parents, good examination passes in subjects such as Latin were seen as passports to tertiary education and to white-collar occupations. Some chose to send their children to school in Christchurch. Hostility also came from officials within the Department of Education. Strachan, however, gained the support of Prime Minister William Massey, who visited the school in 1920, and of ministers of education such as C. J. Parr and Harry Atmore. His reforms were endorsed by a royal commission in 1925; a consultative committee in 1943 recommended that Strachan's system should form the basis of the post-primary curriculum.
Strachan was a notable amateur radio expert, credited with having sent New Zealand's first radio signal (the length of a back garden in Dunedin). His interest in the potential of wireless telegraphy to create international goodwill through better communication had led him to develop a school radio station, ZL3A1, where pupils could enhance their knowledge of the new technology while sharing ideas with their counterparts overseas. A lifelong interest in international affairs resulted in his leading the New Zealand delegation to the conference of the Institute of Pacific Relations in 1931. He gained a Carnegie Foundation travel grant to the United States and Europe in 1938. He was also chairman of the reception committee that met Charles Kingsford Smith after his epic trans-Tasman flight in 1928.
Mary Strachan had died in 1923, and James married Vera Agnes Barrell at Waikuku Beach, near Rangiora, on 3 January 1934. He retired in 1948, although he relieved at Greymouth Technical School, Waimate High School and Christ's College. He enjoyed painting and photography. His publications included The school looks at life (1938), an account of the Rangiora experiment. An autobiographical memoir was left uncompleted at his death.
James Strachan died at Christchurch on 30 September 1973, survived by his wife, daughter and two sons. He had become one of New Zealand's most influential educators. His experiments at Rangiora were discontinued by his successor, J. F. Moffatt, but were later widely adopted in the New Zealand school system. His courage, resolution and idealism were admired by contemporaries such as Frank Milner, rector of Waitaki Boys' High School. He believed firmly in the merits of co-education, yet he remained an enthusiastic supporter of a practically oriented domestic curriculum for most girls. He was remembered by former pupils as having been kind, fair and easily approachable; he enlivened school assemblies with readings from various books, and by singing in a resonant Scottish voice. Occasionally his idealistic high-mindedness led him to disparage the extra-curricular pursuits of his students: he disapproved of their attending dances and films, and suspected them of having depraved tastes in reading. But these asperities were outweighed by his lasting influence on secondary education in New Zealand.