The Evolution of Morality

This Science Times article on the evolutionary origins of morality makes this supposition:

...liberals assigned much less importance to the three moral systems that protect the group, those of loyalty, respect for authority and purity.

Conservatives placed value on all five moral systems but they assigned less weight than liberals to the moralities protective of individuals.

So while conservatives fancy themselves the "rugged individualist", John Wayne-style, actually, they're simply expressing a collective protectionism towards their group.

Later in the article, the idea is challenged:

“It is obvious that liberals emphasize the common good — safety laws for coal mines, health care for all, support for the poor — that are not nearly as well recognized by conservatives,” Dr. de Waal said.

The researcher became interested in this social expression of an underlying evolutionary trait of humans to feel revulsion towards that which may make them less likely to survive. Disgust is important to our survival, and religion's systematizing it lead to the success of those groups. Interesting.