I think the surrounding culture has influence over a general sense of morality among atheists. Humans are naturally an altruistic species but we are higher functioning than most of the other species that exhibit the same behavior. I guess that is what people consider consciousness. The overriding truth of reality is its indifference toward the plight of man. The most moral are stricken with horrific diseases and misfortune and the most vile are often rewarded with good luck and fortune. It makes no difference either way. Sure, good fortune can come and often does to people whom act in a moral way. Just like being an ass can come back around at you. But that is a function of your actions and not the punishment or reward by a deity. You reap what you sew for the most part in regards for interaction with others.