Nova Scotian William D. Tait received his B.A. from Dalhousie and his M.A. from Harvard University. Tait joined the staff of McGill in 1909 as lecturer in experimental psychology; he was promoted to Assistant Professor in 1914, Associate Professor in 1921 and Professor in 1924. From 1924 until his death, he served as chairman of the Department. Apart from teaching and research, largely in educational psychology, Tait acted as a government consultant; he was a member of both the Industrial Conference in Ottawa (1919) and the labour committee of the Federal Cabinet. Dunlop passed away in 1945.

Sir Thomas James Tait was born on July 24, 1864, in Melbourne, Quebec.

He was a prominent railway, mining, and industrial executive. Educated at McGill University, he entered the service of the Grand Trunk Railway in 1880, and by 1903 he was manager of transportation with Canadian Pacific Railway company. In 1903, he was appointed Chairman of Commissioners of the Victorian Railways, Australia. During seven years in Victoria, he turned an annual deficit into a profit, improved and increased the railways' rolling stock, and initiated electrification of the railways of Melbourne (1913). The red carriages of the new electric trains were known as “Tait cars”. He was knighted in 1911, before returning to Canada.

He was also a president of Parkhill Gold Mines, the Montreal branch of the Royal Empire Society, and the Fredericton and Grand Lake Coal and Railway Company. In 1928, he received the honorary degree of LL. D from the University of New Brunswick.

In 1890, he married Emily St Aubert Cockburn. He died on July 25, 1940, in St. Andrews, New Brunswick.