The relative yields for addition of the OH radical at the various positions of 1- and 2-naphthol provide a measure of the spin polarizability in the naphthols. The observed yields show that addition occurs predominantly at the naphthol positions that are conjugated with the OH substituent. They also show that the electronic structures of the naphthols are significantly affected by a concerted interaction between the OH substituent and the unsubstituted ring and that this effect is somewhat greater when the OH substituent is adjacent to the naphthol bridge. The yields for addition at the different naphthol positions correlate with the local spin polarizabilities at reactive carbons in the naphthol. The spin polarizability may be a general property governing the reactivity of closed-shell molecules with radicals.