The idea that creativity may have given Homo sapiens a survival edge over Neanderthals has been around a long time, said senior author Dr. Claude Robert Cloninger, a professor emeritus in the psychiatry and genetics departments at Washington University in St. Louis. But that's a tricky case to prove, as we still don't know how creative Neanderthals actually were, he said.
"The problem with evaluating creativity in extinct species is, of course, you can't talk to them," Cloninger told Live Science. So an international team of researchers, led by a group at the University of Granada in Spain and the Washington University School of Medicine in St. Louis, looked at genes to examine what distinguished humans, including their creative ability, from their distant relatives.
The researchers had previously identified 972 modern genes that regulate three distinct systems of learning and memory in Homo sapiens: emotional reactivity, self-control and self-awareness. The emotional reactivity network involves the ability to form social attachments and learn behaviors while the self-control network involves the ability to set goals, cooperate with others and make tools.
The self-awareness network, on the other hand, involves "episodic learning" or remembering and improving upon past behaviors and autobiographical memory of a person's life as a narrative with a past, present and a future "within which the person can explore alternative perspectives with intuitive insight and creative imagination," according to the study.
Self-awareness is "what enables us to have divergent, original creative thinking [and to] be very flexible," Cloninger said.
In the new study, the researchers analyzed DNA previously taken from Neanderthal (Homo neanderthalensis) fossils, modern humans (Homo sapiens), and chimpanzees (Pan troglodytes). They found that the genes related to the oldest network — emotional reactivity — were identical among Homo sapiens, Neanderthals and chimpanzees. But the chimpanzees completely lacked the genes that led to self-awareness and self-control in humans.
Some, but not all, of those genes were present in Neanderthals. "The Neanderthals were about halfway between the chimps and modern humans'' in the number of these genes they carried, Cloninger told Live Science.
What's more, 267 of those 972 genes were unique to Homo sapiens, and they were all so-called regulatory genes. In other words, they dial the activity of other genes up or down. These genes — which were absent in chimpanzees and Neanderthals — regulate the brain networks involved in self-awareness and creativity.
Unique to Homo sapiens
The emotional reactivity network evolved in monkeys and apes about 40 million years ago, the self-control network evolved a little less than 2 million years ago, and the self-awareness and creativity network emerged just 100,000 years ago, when humans were under pressure from a changing climate that reduced the supply of food and other resources necessary for survival, Cloninger said.
Then, some 40,000 years ago, Homo sapiens with "unprecedented cultural and technological sophistication" began rapidly replacing Neanderthals around the world, according to the study. This sophistication was likely driven by our Homo sapiens ancestors' creativity and self-awareness, which enabled them to live longer, healthier lives, the authors said.
Such longevity would have allowed a longer learning period for kids and adolescents and thus more time to accumulate knowledge. Living longer, healthier lives would have also encouraged cooperation among individuals and extended communities to promote the success of their children, grandchildren and others in the community. That, in turn, would enable "the technological innovativeness, behavioral flexibility, and exploratory disposition needed to allow Homo sapiens to spread throughout the world more successfully than other human lineages," the authors wrote.
Still, the study comes with several limitations, including that traits such as creativity and self-awareness are complex and that Neanderthals are no longer around, making it difficult to assess them solely based on their genes. (For example, a person's environment can also influence their personality and behavior.) Indeed, some researchers are not convinced that comparing the modern human genome to that of an extinct species can lead to robust conclusions.
"We do not know the causal link between genetics and these higher traits, even if the authors identified networks of genes that are associated with some measures of self-awareness, creativity or prosocial behavior," said Thomas Suddendorf, a professor in the School of Psychology at the University of Queensland in Australia who was not part of the study.
So, although the findings are interesting, "I would caution against drawing any firm conclusions from such data about extant, let alone about extinct, species," Suddendorf told Live Science in an email. It is "undoubtedly" the case that humans are more creative than other animals currently living, including chimpanzees, he said.
The authors noted in the study that they "cannot exclude the possibility that Neanderthals had genes that were not present in [Homo] sapiens and influenced their personality and learning abilities." In other words, Neanderthals may not have had the same genes for creativity and self-awareness, but rather their own set of genes that we don't understand.
The findings were published April 21 in the journal Molecular Psychiatry.
Originally published on Live Science.