2 Neoteny and Evolutionary Psychology

He who wishes to decide whether man is the modified descendant of some pre-existing form, would probably first enquire whether man varies, however slightly, in bodily structure and in mental faculties; and if so, whether the variations are transmitted to his offspring in accordance with the laws which prevail with the lower animals.

– Charles Darwin, The Descent of Man (1871)

We probably remember about 1/10,000 of a lived life: Amounting to about 204,960 seconds (thus, each second representing a memory; or about 57 to 60 hours); vocabularies average 50,000 words; episodes are made up of objects and actions. About 2 1/2 days of information. And, this information store is constantly changing and updating itself. The belief that it is much larger is based on the fact that we live in a networked world of people, technology, and information sources that allows us to feel a sense of a much larger mnemonic world.

– Jay Seitz (2019, “Mind Embodied: The Evolutionary Origins of Complex Cognitive Abilities in Modern Humans”)

There is a major organizing concept that drives all human growth and development that will inform the backbone of our story. It’s called “neoteny” or the retention of juvenile characteristics in the adult and a major feature of human evolution.

Neoteny is the slowing down of brain and bodily development through infancy, childhood, and adolescence resulting in the heightened cognitive, affective, and creative abilities of human adults. And those capabilities are found nowhere else in the animal kingdom although there are glimpses of many of those abilities in other species.

Ancestors of modern humans (“hominins”) include the Great Apes (“hominids”), that is:

• Archaic humans
• Orangutans
• Gorillas
• Bonobos and chimpanzees

Hominid families also have an extensive developmental period similar to ours. Let’s see what this means.

Neoteny

Some of the brightest non-human primates are the bonobos, which are closely related to members of the chimpanzee family. They communicate vocally with their kin but use similar calls or vocal signs to mean diverse things so that the receiving bonobo must determine the meaning from the context, a characteristic of modern life not at all unfamiliar to us.

They possess the capacity for self-awareness as they easily pass the mirror self-recognition test. That is, they can distinguish between themselves and others while looking into a mirror. But they also display a keen interest in aspects of themselves such as a red mark placed surreptitiously on their face and the assumption is that this behavior exemplifies self-awareness. So, it turns out we may not be the only creatures on the planet that possess self-awareness or higher-order or secondary consciousness.

Moreover, their facial expressions and hand gestures are very similar to humans and, what’s more, are easily understood by us suggesting that both species—bonobos and humans—are picking up on intentional states conveyed by way of the body.

They engage in observational learning by watching others, including other humans, a sophisticated way to learn that young children and a few other species quickly pick up on.

But, most extraordinarily, they have been taught up to 3,000 words using geometric-like symbols called lexigrams. They can communicate with about 500 or so of them, as they cannot intone human word sounds themselves, but can respond with these lexicographical tokens to spoken sentences in communication with others, including humans.”

Excerpted from my book (pp. 107-108, see below):

Mind Embodied

Bonobos (Pan paniscus) and chimpanzees (Pan troglodytes) share close to 98% of their genome with humans (Homo sapiens) and, as a result, are actually more similar to modern humans than they are to gorillas. Nonetheless, bonobos and chimpanzees diverged from each other close to one million years ago and differ significantly in morphology, behavior, cognition, and emotion.

Bonobos populations are matriarchal with females forming tight bonds against males through “same-sex sociosexual contact that is thought to limit aggression.” Males are never the “alpha.” Unlike chimpanzees, they do not cooperatively hunt, use tools or exhibit lethal aggression. Moreover, frequent non-reproductive sexual behavior is observed at all ages and between all partner types and is believed to encourage tolerance and conflict resolution, among other things.

Bonobos: Unique in Mind, Brain, and Behavior

– Background notes courtesy of the Department of Evolutionary Anthropology, Duke University (one of their books, above)

Evolutionary Psychology

PowerPoint Presentation: Evolutionary Psychology

Why do we need to turn to evolutionary theory?

Charles Darwin, published a monumental work in 1859, The Origin of Species. He argued that diversity in nature (i.e., phenotypic variation) is a consequence of heritability of traits that confer some advantage to a species in their present environment.
We call this latter process adaptation. The interaction between organisms and their environments.

The driving force of evolution Darwin called natural selection. Thus, species and traits evolve because they confer some adaptive advantage in the species’ current environment. To put it another way, selection pressures in the physical and social environment cause the organism to react and change (or not) in some way.

If we want to understand how humans think, feel, and behave, we need to understand how we evolved into modern humans (H. sapiens). The social and physical conditions that shaped modern hunter-gatherer societies are very similar to our own in most parts of the world.

Modern humans (H. sapiens) evolved approximately 200,000 years ago. The wealth of scientific evidence suggests our ancestors lived in northern Botswana in South Africa.

There are two views of our African genesis. One view is that earlier hominids (e.g., H. erectus) left southeast Kenya approximately one million years ago and then evolved into H. sapiens in different parts of the world. The other view is that modern humans evolved from earlier hominids in Africa but did not leave until approximately 200,000 years ago when they settled throughout the globe. Thus there are two plausible migrations or diasporas. In either case, we call both views the African Genesis Hypothesis.

Scientific Evidence for the African Genesis Hypothesis

All the world’s languages seem to be derived from a “proto-” or “Ur” language that had its origins in Southeast Africa.

The similarity of DNA from the mitochondria of both females and males from different human cultural groups points to a common female ancestor (i.e., “Mitochondrial Eve”) and a common male ancestor (i.e., “Mitochondrial Adam”) in SE Africa.

The paleontological evidence is more mixed. Remains of H. erectus, an earlier hominid, have been found outside Africa suggesting an earlier diaspora. Similarly, there is now evidence that some modern Europeans and Australians have a small amount of DNA from another earlier hominid, H. neanderthalensis. This indicates some genetic mixing in modern hominids groups rather than pure replacement.

Natural Selection

Natural selection is the main, but not only force of evolutionary change.

There is also sexual selection (i.e., competition among males for available females) and artificial selection (i.e., selective breeding). Mutations, genetic drift, gene flow, geographic isolation, and exaptation also effect evolutionary change.

For instance, feathers originally evolved for thermoregulation and were only later exaptated for flight. We call the latter process, nonadaptive change.

Species and Varieties (Subspecies)

A species is a naturally occurring biological group that interbreeds.

A subspecies or variety is a biological subgrouping as a result of significant phenotypic variation due to geographic isolation or other factors.

Is race (i.e., a subspecies or variety) a significant biological subgrouping? No, all human groups interbreed and are significantly geographically dispersed. Thus, race is not a valid biological category. Race is a cultural construct not a valid biological construct.

Indeed, there is more variation within an ethnic group (85% of all human genetic variation) than between ethnic groups (7%) or between human groups that live on different continents (8%).

Why do identical twins appear to have very similar personalities? Culture and environment also play a huge role in human development.

The mental abilities, personalities, and behaviors that we exhibit, first existed on the African savannah nearly 200,000 years ago. At that time, early modern humans lived in small social groups of approximately 200 women, men, and children.

What, at minimum, would early modern humans have needed to survive and reproduce?

Evolutionary psychology posits that they would have required the following to survive and reproduce as a species:

(1) Social and emotional intelligence, that is, the ability to detect cheaters and enforce the social contract, ability to recognize kin from nonkin, the ability to read facial expressions and body language, and the ability to “read” other people’s intentions.

(2) Visuospatial intelligence for foraging and hunting.

(3) Communicative intelligence using linguistic and gestural “languages.”

There must have also been some central organizer to integrate all these different abilities. Could the frontal lobes be the seat of “executive functions”? The frontal lobes are one of the most evolutionarily advanced parts of the brain.

The frontal lobes seem to be implicated in attentional deficits, depression, obsessive-compulsive disorders, and in some severe forms of mental illness (e.g., schizophrenia). They also play a significant role in working memory and, presumably, rational thought processes.

Until recently, it was believed that the earliest symbolic and aesthetic uses by early modern humans consisted of cave paintings and other artifacts found principally in Europe (e.g., Lascaux, France, ~35,000 years ago). New evidence suggests that much earlier evidence of human artifacts dates back to locales in S. Africa, ~70,000 years ago.

This implies that the evolution of the use of humans of symbolic artifacts (e.g., paintings, notations) was slow and gradual, not abrupt. Human symbolic cultures began in Africa and possibly other parts of the world, not more abruptly in Europe as originally believed.

Merlin Donald, a cognitive psychologist, suggests that human cultures evolved in four (4) stages: (a) episodic or primate culture, (b) mimetic culture, (c) mythic culture, and (d) theoretic culture.

Episodic culture is characteristic of primates (including humans) who are able to grasp episodes or “events” and store them in episodic memory.

Mimetic culture is characteristic of early modern humans who evolved the capacity for imitation, that is, the ability to link an action with a perceived event. In Jean Piaget’s theory of the development of the child, this is the first stage of human ontogeny: the sensorimotor phase. Currently, the study of the role of the body in thought is called, “embodied cognition.”

Mythic culture is characteristic of later developing hominid groups in which the center or driving force of culture revolved around myth and ritual. Language began to evolve during this period, ~250,000 years ago, as it became they central carrier of cultural myths.

Theoretic culture evolved during the Upper Paleolithic period over the last 200,000 years. It was characterized by the use of symbols and creative and rational thought, reaching its zenith in modern Greek culture.