Neandertalogy: Why Should Psychologists Study Neandertals?

Neandertals are our closest human cousins but they went extinct about 30,000 years ago. But why should psychologists (i.e., anyone in any discipline of psychology) aid in the study of Neandertals? Psychologists study children, adolescents, young adults, and older adults. They study dying and death. They study groups and organizational behavior. They study animals. They study normal and abnormal behavior. They study evolution. They study numbers, their origin, and how to make decisions from them. In short, psychologists study all aspects of behavior. I have even published personality profiles of dead people like Adolf Hitler (Coolidge, Davis, & Segal, 2007) and mythical people like Fitzwilliam Darcy from Jane Austin’s Pride and Prejudice (Coolidge, 2016). Psychologists should study Neandertals because anthropologists and archaeologists need our help! There is no virtually no aspect of psychology that does not address Neandertals’ lives and their extinction. And here are some examples of how the many disciplines of psychology can contribute to the understanding of our extinct cousins:

Biopsychology/Neuropsychology: Neandertals required 35% more calories just to walk because of their robust (stocky) bodies compared to Homo sapiens living at the same time. They could only obtain these extra calories from meat, although they did have varied diets. However, with thinner more ‘gracile’ bodies, Homo sapiens could rely on less meaty diets. Was a lack of big game a reason for Neandertals’ extinction? Neandertals had about 10% bigger brains than Homo sapiens. Did that make them smarter? If so, why did they go extinct? Homo sapiens had bigger parietal lobes, bigger temporal lobes, bigger cerebellums, bigger olfactory bulbs but smaller occipital lobes. What were the potential neuropsychological consequences of these brain differences, if any? If there were behavioral consequences, did they have anything to do with Neandertals’ extinction? Interestingly, a recent study showed that modern brain shape (smaller, rounder) in Homo sapiens only occurred over the last 100,000 to 35,000 years ago.

Quantitative Psychology and Statistics: Brains do not fossilize but skulls do. How do anthropologists (and specifically paleoneurologists) know that Neandertals’ brains were shaped differently than Homo sapiens? Interestingly, some anthropology programs do not even require a basic statistics course and few require an advanced statistics course (in graduate programs). So how can we know that Neandertals had differently shaped brains than Homo sapiens? Determining brain shape differences from skulls requires factor analysis or principal components analysis, and most graduate programs in psychology do offer multivariate statistics courses.

Developmental Psychology and Geropsychology: Teeth preserve well in the fossil record because they are so hard (while finger bones typically do not). We know that Neandertals’ molars erupted earlier than in Homo sapiens, which suggests that Neandertals matured faster. What were the consequences of this earlier molar eruption? Did Neandertals have a faster ‘speed of life’? Did they have a shorter childhood and adolescence? What are the potential consequences for adult lives if there was a shortened childhood/adolescence? In 1908, a Neandertal skeleton was found in La Chapelle, France. He was called “the old man of La Chapelle” because he had lost most of teeth, had arthritis, and degenerative bone disease. His age at death is estimated to be 35 to 40 years old. Did Neandertals die younger than Homo sapiens? If they did, was their lifestyle or diet responsible? Or genetically were they capable of living as long as Homo sapiens?

Social Psychology: Neandertals lived in smaller groups than Homo sapiens. Their group size is estimated to be about 20 to 40 individuals, while Homo sapiens may have evolved in groups of 100 to 150 (search for the works of anthropologist Robin Dunbar for the latter). Why was there such a large difference in group size between these two human cousins? Keeping track of allies and enemies is essential in all primate groups. Were Neandertals unable to keep track of larger numbers of people? Did they simply prefer smaller groups? Are there social psychological theories that might address this difference?

Cognitive Psychology: Neandertals often hunted by thrusting fire-hardened spears into the sides of red deer, wild horses, rhinoceroses, and wooly mammoths. Homo sapiens invented bow-and-arrow technology about 80,000 years ago, which is a much safer hunting technique. Did this reflect differences in executive functions? Could Homo sapiens plan better and create safer hunting techniques because of enhanced executive functions? Were the differences in hunting techniques due to greater working memory capacity in Homo sapiens? Might the latter have entailed a larger visuospatial sketchpad, phonological storage, or episodic buffer? Could Homo sapiens rehearse alternative hunting strategies in their minds, thus saving them from fatal trial-and-error?

Clinical and Forensic Psychology: Were Neandertals braver than Homo sapiens? Were they more xenophobic? Did Neandertals have a different chronotype (morning versus night preferences) because they had larger occipital lobes, thus potentially giving them advantages to hunting in the late afternoon and evening when large game are often more active. There are far many more instances of cannibalism among Neandertals over the past 120,000 years than for Homo sapiens. In some cases, Neandertals cannibalized babies and juveniles, and they processed that meat just as if they were deer or other animals. In fact, in some instances, the cannibalized bones were found among animal bones indicating that food was plentiful. Was Neandertal cannibalism, thus, a tradition or gustatory practice? Neandertals survived over 250,000 years or more. What rules or laws guided their behavior in groups?

Behavioral Genetics: Recent genomic studies show that Neandertals and Homo sapiens had a common ancestor about 600,000 years ago and their evolutionary lines diverged shortly after. There is some evidence there was limited interbreeding between these two human types but only relatively recently, about 80,000 to 40,000 years ago. They share over a 99% similarity in their DNA but that may indicate the 1% difference may have been critical to the Neandertal extinction. What did the 1% difference in DNA mean for brain/body structure, cognition, immunity, or behavior? What did the genetic introgression between the two human types mean for each? Did Homo sapiens really get red hair, depression, addictions, and Crohn’s disease from Neandertals?

Existential Psychology: Neandertals intentionally buried their dead, as did Homo sapiens but only the latter added grave goods like beads and ornamental ivory disks. There is very sparse evidence for any grave goods in Neandertal burials, e.g., pollen and an animal jaw, and it is extremely controversial as to whether the latter was intentional or accidental. Why do humans employ grave goods? Is it to assuage the feelings of the survivors or does it represent beliefs in something spiritual, religious, or supernatural? What does the absence of grave goods in Neandertal burials say about their view of the future or an afterlife?

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Evolutionary Psychology: The course of evolution is characterized by long periods of stasis, sudden change (punctuated equilibrium), and extinctions. Why did Neandertals go extinct after living in Europe, the Middle East, and Asia successfully for hundreds of thousands of years? Modern humans (with differently shaped and smaller brains) moved into Europe only about 45,000 years ago. Neandertals went extinct shortly after. Did Neandertals already carry the evolutionary seeds of their own demise like countless numbers of other species in life’s history? Or did modern Homo sapiens put an evolutionary pressure upon Neandertals that the latter could just not handle?

The Psychology of Art and Esthetics: What constitutes symbolism? According to the gold standard (sic) of all present human knowledge, Wikipedia, it is ‘something’ that represents an idea. When Pavlov’s dog salivated to a bell, was the bell, therefore, a symbol? When is a symbol representative of abstract thinking and when is it simply an example of classical conditioning? About 100,000 years ago, a Neandertal took a small round pebble with a straight fissure in it, and he or she cross-hatched a tangential line across the fissure. Many anthropologists claim that this etching is symbolic. About 41,000 years ago, a Neandertal etched a partial tic-tac-toe design in a Gibraltar cave. Some anthropologists claim it was evidence for symbolism and abstract thinking. Is this a fair assumption or should we invoke Occam’s razor (the simplest explanation is safer)? If we invoke Occam’s razor, are we being unfair to Neandertals?

In summary, psychologists should help anthropologists and archaeologists because we are experts in virtually all aspects of behavior. Neandertals pose difficulties to all scientists because Neandertals are extinct but much can be inferred about their behavior from their bones and artifacts. Thus, psychologists should not shy away from aiding other scientists in unraveling the mysteries of Neandertal lives and their extinction. Viva Neandertalogy!

Want to read more?

Wynn, T., & Coolidge, F. L. (2012). How to think like a Neandertal. Oxford, UK: Oxford University Press.

And if you’d prefer to read the above book in German:

Wynn, T., & Coolidge, F. L. (2013). Denken wie ein Neandertaler. Trans. C. Hartz. Philipp von Zabern: Darmstadt, Germany.