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There are two additional points worth making about this study. A fairly consistent feature of biological research into sexual orientation has been a clear divergence in the results within females and those within males. By the relevant measures, lesbians tend to situate clearly separate from straight women while by any measure there is overlap between straight men and gay men.

In other words, with this study, whereas you might expect all lesbians to evidence a more 'masculine' startle response than other women, you would expect some straight men to evidence a less 'masculine' startle response than some gay men. In fact, what you often tend to see is two distinct subgroups of men - one best described as 'effeminate' and one best described as 'hypermasculine' - with the rest just intermixed amongst the straight men.

This is consistent with studies of prenatal androgen exposure, adult circulating testosterone, brain structure size differentials, secondary sex characteristics, and otoacoustic emission studies (off the top of my head).

I strongly argue that one of the frequent conceptual errors promulgated by researchers is this idea that if you establish a biological basis for sexual orientation amongst, say, women, then that establishes a biological basis amongst men as well (or vice versa). Many of these studies that proclaim evidence of inborn sexuality (actually, near all of them) really only evidence a strong biological component to female sexual preferences, but not to male sexual preferences.