Sexual orientation has a known association with handedness (same-sex-attracted people of either gender have higher odds of being left-handed/ambidextrous than do straight people) so it’s reasonable a priori for a correlation to exist in one sub-population and not the other. Splitting by handedness reduces variance for many sexuality questions — it’s not a sign of p-hacking.
> Sexual orientation has a known association with handedness
That sounds so strange I had to fact-check, and it appears you're right, there does seem to be a measurable association [0].
Perhaps even more interesting, that same article reports: '...the strongest handedness nding for both sexes was a marked tendency for participants who described themselves as ambidextrous also to describe themselves as bisexual'. How weird.
