No one has asked me this question, but I find myself thinking about it nonetheless: do I read the bios before I read the poems? The short and easy answer is no. I usually read the name of the person so I can get a sense if the poet is male or female because in 95% of the poems, the voice of the narrator is the same sex as the poet (though not always). After that, I read the poems. The bio just isn't that important to me. It's the poems that speak.
That said, I often receive submissions from a poet more than once. Sometimes from people I've published. When that happens, I can't help but have an idea about the poet because I've not only read the bio before, but very often I've read the poet's poems many times before, like I do all the poems that I accept. In those cases, I can't help but understand a bit more about the voice of the poet. I also have an understanding about the poet's personal history that sometimes influences my understanding of the poems sent to me.
However, even with this, I try not to let it affect my judgment. I've declined poems from poets who I've published before. I've also accepted poems from poets I've published before. I try to do my best to be fair in all those cases and I'm sure that I sometimes fail, but I make the effort each and every time. I don't reread the bios of people I've already published. In fact, I don't read the bios of new poets I'm about to publish until I lay out the pages and start looking for links to their work. In my opinion, the poems are the important thing, not the bio.