Why is it that we care about other people? Why do we have those feelings? Also, at a cognitive level, how is that implemented? Another way of asking this is: Are we predisposed to be selfish? Do we only get ourselves to be cooperative and work for the greater good by exerting self-control and rational deliberation, overriding those selfish impulses? Or are we predisposed towards cooperating, but in these situations where cooperation doesn't actually pay, if we stop and think about it, rationality and deliberation lead us to be selfish by overriding the impulse to be a good person and help other people?     

DAVID RAND is an associate professor of psychology, economics, and management at Yale University, and the director of Yale University’s Human Cooperation Laboratory. David Rand's Edge Bio Page

A new thinking came about in the early '80s when we changed from rule-based systems to a Bayesian network. Bayesian networks are probabilistic reasoning systems. An expert will put in his or her perception of the domain. A domain can be a disease, or an oil field—the same target that we had for expert systems. 

The idea was to model the domain rather than the procedures that were applied to it. In other words, you would put in local chunks of probabilistic knowledge about a disease and its various manifestations and, if you observe some evidence, the computer will take those chunks, activate them when needed and compute for you the revised probabilities warranted by the new evidence.

It's an engine for evidence. It is fed a probabilistic description of the domain and, when new evidence arrives, the system just shuffles things around and gives you your revised belief in all the propositions, revised to reflect the new evidence.         

JUDEA PEARL, professor of computer science at UCLA, has been at the center of not one but two scientific revolutions. First, in the 1980s, he introduced a new tool to artificial intelligence called Bayesian networks. This probability-based model of machine reasoning enabled machines to function in a complex, ambiguous, and uncertain world. Within a few years, Bayesian networks completely overshadowed the previous rule-based approaches to artificial intelligence.

Leveraging the computational benefits of Bayesian networks, Pearl realized that the combination of simple graphical models and probability (as in Bayesian networks) could also be used to reason about cause-effect relationships. The significance of this discovery far transcends its roots in artificial intelligence. His principled, mathematical approach to causality has already benefited virtually every field of science and social science, and promises to do more when popularized. 

He is the author of Heuristics; Probabilistic Reasoning in Intelligent Systems; and Causality: Models, Reasoning, and Inference. He is the winner of the Alan Turing Award. Judea Pearl's Edge Bio Page 

One of the things that has been of particular interest to me recently is how you get the connectivity amongst all of these different constituents in a city. We know that we have high-ranking elites, leaders who promote and organize the development of monumental architecture. We also know that we have vast numbers of ordinary immigrants who are coming in to take advantage of all the employment, education, and marketing and entrepreneurial opportunities of urban life. 

Then you have that physical space that becomes the city. What is it that links all of these physical places together? It’s infrastructure. Infrastructure is one of the hottest topics in anthropology right now, in addition to being a hot topic with urban planners. We realize that infrastructure is not just a physical thing; it’s a social thing. You didn’t have infrastructure before cities because you don’t need a superhighway in a village. You don’t need a giant water pipe in a village because everybody just uses a bucket to get their own water. You don’t need to make a road because everyone just walks on whatever pathway they make for themselves. You don’t need a sewer system because everyone just throws their garbage out the door.

MONICA SMITH is a professor of anthropology at the University of California, Los Angeles. She holds the Navin and Pratima Doshi Chair in Indian Studies and serves as the director of the South Asian Archaeology Laboratory in the Cotsen Institute of Archaeology. Monica Smith's Edge Bio Page