Source: Module 1, Chapter One | Course: A Brain-Mind Odyssey (UC Berkeley)
Tags: origins, human evolution, hominin, Australopithecus, Homo sapiens, brain size evolution, mind-body problem, consciousness, mind, mental experience, Paleolithic cave art, shaman, conspecific
This chapter traces human origins from early hominin ancestors on the East African savannas through the expansion of brain size and behavioural complexity. It introduces the philosophical distinction between mind and brain, defines consciousness and mental experience, and raises the mind-body problem: the still-unresolved question of how subjective experience relates to the physical brain.
Paleolithic cave art
Artistic works found in caves dating from ten thousand or more years ago, among the earliest evidence of human symbolic and creative behaviour.
Shaman
An individual believed to be particularly skilled at accessing states of mind that serve as sources of knowledge and power for the community. Shamans are healers, respected across cultures, who are said to communicate with animals, plants, and natural elements in ways outside the scope of contemporary science.
Hominin
The group of primates that includes modern humans and their ancestors, extending back roughly five million years. Three primary genera: Ardipithecus, Australopithecus, and Homo.
Conspecific
An organism belonging to the same species as another. Used in this context to describe violence and killing among members of the same species.
Mind
The collection of mental experiences.
Mental experiences
Subjective, first-person, internal experiences, including thoughts, feelings, perceptions (visual, auditory, olfactory, gustatory, tactile), mental images, and sense of self.
Consciousness
The capacity to be aware of mental experiences, to have an experience of what it is like to be.
Mind-body problem
The philosophical question: what is the relationship between our mental experience and the physiology of our body and brain? The fact that brain and mind are intimately related does not prove that mind is solely a product of brain.
Hominins are classified into three primary genera. The key species and their approximate dates:
Ardipithecus ramidus – ~4.4 million years ago (mya)
Australopithecus afarensis – ~3 to 4 mya
Australopithecus africanus – ~2 to 3 mya
Australopithecus robustus – ~1 to 2.5 mya
Homo habilis – ~1.4 to 2.3 mya
Homo erectus – ~200,000 to 1.9 mya
Homo neanderthalensis – ~30,000 to 300,000 years ago
Homo sapiens – ~200,000 years ago to present
Most of the oldest hominin fossils have been found on the plains of East Africa.
Brain (cranial) volume increased substantially over the course of hominin evolution:
Ardipithecus ramidus – ~350 cc
Australopithecus africanus – ~500 cc
Homo habilis – ~650 cc
Homo erectus – ~1200 cc
Homo neanderthalensis – ~1400 cc
Homo sapiens – ~1400 cc
Part of this increase can be attributed to increasing body size. The expansion of brain size is accompanied by more sophisticated behaviours: tool use, nuanced social interaction, language, mathematical skill, complex problem-solving, and the capacity to construct elaborate explanatory frameworks.
Humans have a primal capacity for fear and violence, and the ability to create and deploy powerful weapons has magnified this. At the same time, humans possess a tremendous capacity for kindness, trust, love, and compassion.
The course defines mind as the collection of mental experiences, and consciousness as the capacity to be aware of those experiences. The mind-body problem asks how subjective experience relates to the physical brain. A common assumption is that mind cannot exist without something like a brain, but intimate correlation between brain and mind does not prove that mind is solely a product of brain.
The HAL 9000 thought experiment (from 2001: A Space Odyssey) illustrates the problem: a machine may behave as though it has subjective mental states, executing sophisticated intentional behaviours, yet we have no way of knowing whether this is accompanied by genuine mental experience.
⚠️ Know the three hominin genera (Ardipithecus, Australopithecus, Homo) and be able to place key species on a rough timeline.
⚠️ Brain size figures (in cc) for the major species are commonly tested. Note that Neanderthals and Homo sapiens have similar cranial volumes (~1400 cc).
⚠️ Be precise with the definitions of mind, mental experience, and consciousness. They are defined in specific, overlapping ways in this course.
⚠️ The mind-body problem is a recurring theme. Understand the distinction: correlation between brain and mind does not equal causation (mind as solely a product of brain).
Q: What are the three primary genera of hominins?
A: Ardipithecus, Australopithecus, and Homo.
Q: What is the approximate cranial volume of Homo erectus compared to Homo sapiens?
A: Homo erectus had a cranial volume of roughly 1200 cc, while Homo sapiens averages about 1400 cc.
Q: Define consciousness as used in this course.
A: Consciousness is the capacity to be aware of one's mental experiences, to have an experience of what it is like to be.
Q: What is the mind-body problem?
A: The question of what the relationship is between our subjective mental experience and the physiology of our body and brain. The close relationship between brain and mind does not prove that mind is solely a product of the brain.
Q: What does the term "conspecific" mean?
A: Belonging to the same species. In context, it refers to violence and killing directed at members of one's own species.
Q: Why is the HAL 9000 example relevant to the mind-body problem?
A: HAL behaves as though it might have subjective mental states, but we cannot know whether sophisticated intentional behaviour is accompanied by genuine mental experience. It highlights the gap between observable behaviour and inner experience.
Paleolithic, cave art, shaman, healer, hominin, Ardipithecus ramidus, Australopithecus afarensis, Australopithecus africanus, Australopithecus robustus, Homo habilis, Homo erectus, Homo neanderthalensis, Homo sapiens, cranial volume, brain size evolution, conspecific, mind, consciousness, mental experience, mind-body problem, HAL 9000, 2001 A Space Odyssey, East Africa, human evolution, subjective experience, first-person experience