The only evidence I'd offer against it is the observation that many boys go through a homosexual phase before genuinely growing out of it. But on the whole it seems a useful insight; I suspect that the Sandfords would cope with the argument - their approach to the altering of the alignment of the homosexual is ultimately mystical not 'scientific'. And for me the suggested cause of being 'BL' does ring some bells - though my AoA means I can tick the box 'Gay' these days with a reasonably straight face (groan - sorry); he's a very cute 31 yo...