Your fingers grasping the pages of this newspaper, and your eyes roving these words, bear a remarkable resemblance to the fingers and eyes of man's closest relatives - the Great Apes (which include chimpanzees, orangutans and gorillas).
Most people acknowledge that humans inherited physical traits from other creatures in the animal kingdom as evolution plodded along toward its crowning achievement.But unsettling new evidence suggests that people may have inherited other key traits from lower animals. The term "unsettling" is apt, because the evidence raises profound questions about what really distinguishes humans from other animals.
People have tried to define human nature since the time of the ancient Greek philosopher Plato. The best definitions focus on so-called "noble" social traits like self-sacrifice, morality and a sense of fairness and justice.
The new evidence suggests morality and a sense of justice may not be uniquely human characteristics. Scientists now have indications that a basic moral code and a crude sense of justice exist in chimpanzees. Such behaviors seem to originate in brain chemicals and structures found in all primates, the animal group that includes humans.
The research involves primatologists, neuroscientists, anthropologists and other experts who are quietly moving toward a redefinition of human nature. The American Association for the Advancement of Science devoted a whole symposium to the topic in February during its annual meeting in Baltimore.
Dr. Frans de Waal, a leading researcher in this field, cites evidence he sees as compelling that morality and ethical behavior evolved like other traits, and exist in both animals and humans.
De Waal is noted for his descriptions of Machiavellian power plays and intrigue among chimpanzees in books like "Chimpanzee Politics" and "Peacemaking Among Primates." He is a psychologist at Emory University in Atlanta and studies ape behavior at the Yerkes Regional Primate Center.
In his latest book, "Good Natured," de Waal describes how primates and other animals share food, respond to social rules, resolve conflicts to their mutual satisfaction and display a crude sense of fair play and justice.
Chimps, for instance, display reciprocity. They readily share food with animals' who shared with them in the past. But they turn their back on stingy chimps who refused to share.
De Waal also witnessed how chimps exact harsh justice on group members who have done wrong. One night two juvenile chimps stayed outside after the others came indoors for dinner. The whole colony had to wait two hours for food. Caretakers kept the late-comers isolated for the night. Next morning, when the entire group was released outdoors, the apes got revenge. They attacked and thrashed the two disobedient juveniles.
Chimpanzees also display empathy, the ability to put themselves into another individual's shoes. Chimps stroke, pat and seemingly console victims of an attack. Females scream at the alpha male, the top dog in chimp society, when he harasses a juvenile or another female.
Dr. de Waal said that such behaviors indicate that apes possess a sense of how other individuals should and should not behave. They suggest the roots of moral behavior, sympathy, fair play, exist elsewhere in the animal kingdom, he added.
The traits, of course, would have had great value from an evolutionary standpoint as animal societies began to emerge. For instance, they would have encouraged cooperation among group members and helped to maintain order.
Next time you give money to a beggar, contribute to charity or support programs for the poor, remember de Waal's observations. Maybe it's not your humanity at work, but your genes. Maybe you're just responding to biological mechanisms similar to those that may influence behavior in apes.
(Distributed by Scripps Howard News Service)