Why do some rise above the flood of supernatural claims that inundate most humans? I’d categorize the rationales for atheism as being predominantly intellectual or predominantly emotional.
Clearly, some atheists combine heart and head reasons for disbelief, but the arguments against supernaturalistic delusions fit into emotional or rational categories. This division probably explains much of the reason for politico-philosophical disparities between atheists.
In the image, I've tinkered with two nebula – dubbed the head and heart nebulae.