Social Cognition
We are social creatures. From early on in life we seek to make sense of events, the world and ourselves, by interpreting the behavior of others. We interpret the motives and behaviors of others on multiple levels through observation, emotional responses, mentalizing, simulation, and cognitive analysis.
Inferring Intentions
People can infer social intentions on the basis of minimal cues.
In 1944, a classic experiment by professors of psychology Fritz Heider and Marianne Simmel demonstrated that rudimentary stick images of nvolving chasing triangles and evading circles.
More recent work has shown that children above age 4 and adults in disparate cultures (Germans and Amazonian Indians) can categorize intentions—chasing, fighting, following, playing, and courting (for adults)— from no more than the motion patterns of computerized v-shaped arrowheads.

This implies a universal capacity of people to infer intentions from rudimentary data.  
  • Accurate judgments of intention from motion cues alone: A cross-cultural study. H. Clark Barrett, Peter M. Todd, Geoffrey F. Miller, Philip W. Blythe. Evolution and Human Behavior, Volume 26, Issue 4, Pages 313-33
Social Facilitation
Research confirms that when we think others can see us, our level of performance changes—we tend to put more effort into our tasks. Well-learned tasks are executed more quickly and accurately, while unmastered tasks are done more slowly and less accurately.

Social Loafing 
People’s effort and creativity tend to decrease when they work in groups, especially when individual performance within a group cannot be evaluated or separated from the success of the entire group. 
The Social Contract 
In the political sense:
A tacit agreement between the government and the governed. The governed agrees to place power in the hands of the rulers or leaders if the authority accepts responsibility for the protection, means of sustenance, and in some cases, the general welfare of the populous.

In the cultural sense: 
  • The parameters of moral behavior. 
  • The "deontological" rules of a society.
Each cultural group formulates parameters for what is viewed as acceptable behavior, and every culture has a set of taboos, a schema for behavior, thoughts and social roles that are disapproved of or forbidden. Some of these taboos [like incest] might have a biological basis but most of them are cultural overlays.

Certain values cross many cultures, but taboos can be very specific to an individual culture. Members of the culture are often conditioned to react to taboos with intense or visceral discomfort. Many cultures invest shame in the taboos.  

Some of the taboos are related to cruel and unjust behavior.  But some of them are related to cultural and religious moral assumptions, habits, traditions, or environmental circumstances.

However, this does not mean that moral and ethical responses are completely relative. There are seemingly universal moral capacities and prosocial behaviors that cross all cultures, but depend on healthy development. 

Examples of "virtue" responses that are based on innate human capacities (requiring appropriate "nurture" to activate): empathy, sympathy, concern for others, interpersonal sensitivity, loyalty, compassion, generosity, a sense of fairness, altruism, courage, kindness, and many more.
Prosocial Behavior:  Altruism 
Acts that benefit others with no obvious benefit to the person performing it are an important aspect of community survival. The “survival of the fittest” and “dog eat dog” concepts of Social Darwinism have not been confirmed by ethology or neurobiology. 

Cooperation, socialization and affiliation, rather than competition, are essential adaptive mechanisms. Reciprocity can occur among all groups and is even observed in bonobos and chimpanzees.

We are not bound by ancient biological imperatives
The human brain is flexible enough to overcome many instinctual predispositions, given healthy neural "wiring" over the lifespan. 

Empathic Imagination enables us to extend our awareness of and concern for those outside of our identified group.