Same here. I've always told myself that it helps my eye keep the position in the text. (Especially helpful I'm distracted and turn away from the screen.) But

Same here. I've always told myself that it helps my eye keep the position in the text. (Especially helpful I'm distracted and turn away from the screen.) But if I really belived that, I'd be doing it consciously, whereas I becoming aware that I'm doing it usually makes me stop... P.S. I'm also slightly(?) OCDish in preferring selections that are integer fractions of the paragrah length. E.g. in a paragraph of 6.3 lines I'll tend to select 2.1 lines at a time (not _that_ precisely of course).