In this talk http://videolectures.net/lms08_hardoon_scca/ (4:58) David says that maximizing the correlation between vectors can be viewed as minimizing the angle between them, and gives two references: Breiman & Friedman 1985, and Hastie & Tibshirani 1990. The second of these is just their textbook, and the first I can't find, although they had a paper around that time about Generalised Additive Models. Basically I can't find where they discuss this. Is the claim true? Does anyone have a definitive reference?