As this is the election season, both those words can be loaded. Social liberals are stereotypically casted as people that like to embrace new experiences, changes, and are open to new ideas. Social conservatives are stereotypically people that like to keep traditions.
Psychologist Jonathan Haight, from the University of Virginia, explores the psychology behind these two groups. In his research, he examines five moral areas: fairness/reciprocity; harm/care; in-group/loyalty; authority/respect; and purity/sanctity.
Fairness is about ensuring people all of all backgrounds have fair justice opportune to them. Harm is ensuring the weak and oppressed are protected. Loyalty is ensuring that no matter the conditions, there is utmost loyalty among groups. Authority ensures there is societal semblance to societal norms and that deviant behaviors are discouraged. Finally, for purity, it is to ensure that society maintains a certain level of decency.
People that were socially liberal generally had high care and fairness moral scores, and these two scores were even higher than the socially conservatives. Despite the slightly lower care and fairness scores, the socially conservatives placed a very high emphasis on the authority, loyalty and purity moral scores, and placed these values significantly higher than social liberals.
Looking at cross countries and cultures, this is true for most around the world. In the Eastern Asian cultures, there is less variance in the authority, loyalty and purity moral scores among socially liberal and conservatives versus North American and European scores.
Certainly this explains the voting patterns among socially liberals and socially conservatives and the differences in ideologies for the various political parties and their supporters. I was hoping a third group would be studied, the Libertarians. There seems to be a rise in this third group, as evidenced by the strong Ron Paul supporters.