Selfish Genes, Social Brains

The gene is obligatorily selfish, but humans are social, caring animals.

Posted Mar 28, 2009

Genes which promote behaviors that increase the odds of the genes surviving are perpetuated. One implication of this simple insight is that evolution concerns the competition between genes using individuals as their temporary vehicles as well as the competition between species. It also means that the genetic constitution of Homo sapiens derives not solely from an individual's reproductive success but from the success of one's children to reproduce. Hunter/gatherers who did not form social connections and did not feel a compulsion to return to share their food or defense with their offspring may have been more likely to survive to procreate again, but given the long period of abject dependency of human infants their offspring may have been less likely to survive to procreate. The result is a selection pressure for the development of information processing operations that could contribute to the formation and maintenance of social connections, including attachment, synchrony, communication, compassion, empathy, social connection, mindreading, deception and the detection of deceit, cooperation, group formation, benevolence, and altruistic punishment - that is, a social brain.

It is the gene that is obligatorily selfish, not the human brain. Humans create emergent organizations beyond the individual - structures that range from dyads, families, and groups to cities, civilizations, and international alliances. These superorganismal structures evolved hand in hand with genetic, neural, and hormonal mechanisms to support them because the consequent social behaviors helped humans survive, reproduce, and care for offspring sufficiently long that they too survived to reproduce. The striking development of and increased connectivity within the cerebral cortex, especially the frontal and temporal regions, are among the key evolutionary developments in this regard. The cerebral cortex is a mantle of between 2.6 to 16 billion neurons with each neuron receiving 10,000 to 100,000 synapses in their dendritic trees. The expansion of the frontal regions in the human brain contribute to the human capacities for reasoning, planning, performing mental simulations, theory of mind, and thinking about self and others. The temporal regions, in turn, are involved aspects of social perception, memory, and communication. The means for guiding behavior through the environment emerged prior to neocortical expansion. The evolutionarily older systems also play a role in human information processing and behavior albeit in a more rigid and stereotyped fashion. The intricately interconnected neocortical regions of the frontal lobes are involved in self control, which permits the modulation of these older systems and the overriding of organismal hedonistic impulses for the benefit of others.

Evidence across human history provides overwhelming support for the supposition that humans are fundamentally social creatures. The average person in contemporary times has been estimated to spend nearly 80% of waking hours in the company of others, most of which is spent in small talk with known individuals. These estimates have been supported in more detailed assessment by Danny Kahneman and colleagues using the day reconstruction method to determine how people spend their time and how they experienced events in their lives on a daily basis. The results of these daily assessments indicated people spend only 3.4 hrs alone, or approximately 20% of their waking hours. The time spent with friends, relatives, spouse, children, clients, and coworkers is rated on average as more inherently rewarding than the time spent alone. Respondents indicated that their most enjoyable activities were intimate relations and socializing - activities that promote bonding and high quality relationships, whereas their least enjoyable activities were commuting and working. These results are consistent with survey data. When asked "what is necessary for happiness?" the majority of respondents rate "relationships with family and friends" as most important, although we certainly do not always act like this is most important.

It is surprisingly easy to overlook the evident and, consequently, to live our lives in nonoptimal ways.

On January 15, 2009, US Airways Flight 1549 departed from New York's LaGuardia Airport for Charlotte, North Carolina when it struck a flock of geese during takeoff. Both engines were disabled, and the heavy aircraft quickly lost the lift it needed to stay aloft. Capt. Sully Sullenberger, who was piloting the plane that day, somehow managed a controlled descent into the Hudson River. The media dubbed the ditching of the plane and the survival of all 155 passengers and crew the miracle on the Hudson, and Capt. Sullenberger was duly heralded as a hero. The ability to control the descent of an 84 ton plane without engine thrust is not something with which humans are naturally endowed. Capt. Sullenberger was not a novice, of course. He was a U.S. Air Force Academy graduate who flew F-4 fighter planes while in the Air Force and had 40 years of flight experience. However, as remarkable as were his achievement relative to what one might normally expect in this situation, Capt. Sullenberger's efforts were not sufficient for the miracle on the Hudson to be achieved.

When Flight 1549 came to a stop in the frigid Hudson River, the passengers and crew scrambled to the wings and inflatable slides of their slowly sinking aircraft. Local commercial vessels from the New York Waterway and Circle Line fleets responded almost immediately, with the first of the vessels reaching the plane within four minutes. The crews of the various vessels worked together to rescue the passengers and crew of Flight 1549, and various volunteers and agencies offered medical assistance. These rescue efforts were not motivated by personal or commercial self-interests, and none were lauded as heroes. Their efforts received less attention because their actions were precisely what we expect of one another.

It is the unusual, not the commonplace, that gets attention. On March 13, 1964, Kitty Genovese parked near her home in Kew Gardens, New York and proceeded to her residence in a small apartment complex. Winston Moseley, a business machine operator who later confessed that his motive was simply to kill a woman, overtook Genovese and stabbed her twice in the back. Genovese screamed, "Oh my God, he stabbed me! Help me!", a call that was heard by neighbors. When one neighbor shouted at the attacker, "Leave that girl alone," Moseley ran away. Genovese, who was wounded and bleeding, moved toward the apartment building slowly and alone. Moseley returned approximately 10 minutes later and searched for Genovese. Finding her nearly unconscious in a hallway of the building, he continued his knife attack on her and sexually assaulted her. The entire attack unfolded over about half an hour, and yet no one responded. The first clear call for help to the police did not occur until minutes following the final attack, and Genovese died in an ambulance en route to the hospital. The number of people who were aware of some aspect of the attack was estimated to be from a dozen to more than three dozen. One unidentified neighbor who saw part of the attack was quoted in a New York Times article as saying "I didn't want to get involved." The notion that people might not go to the aid of another, even a stranger, in dire need led to public outrage. Decades of research led to the conclusion that the ambiguity of the situation and the diffusion of responsibility were contributing factors.

These two news stories illustrate, in very different ways, how invisible forces sculpted by evolution and cultivated by environment act on our species. When commercial captains act against their own financial interests to rescue others on a sinking aircraft, we think nothing of it because we believe it is what any individual in the same situation would naturally do. When observers of a brutal attack do nothing to aid the victim, we are horrified because we believe it goes against who we are as a species. The notion that "what is good for me is good for society" has been a mainstay in economics for the past four decades, but economics has it wrong. Humans are not motivated solely by self interests but rather we work together and help one another when in need. We survive and prosper in the long run through collective concerns and actions, not by solely selfish pursuits.