Evolution and Culture [via a lecutre about brains], part two 8 September 2006Posted by Todd in American Pragmatism, Biology, Cognitive Science, Cultural Sociology & Anthropology, Evolution, Science.
[Note: This is a rough draft, taken from lecture notes. I’ll return later today to clean it up for readability and clarity.]
As I mentioned last night, I’ve been teaching about evolution of human cognition, leading students toward a naturalistic explanation of culture (both its origins and how it functions in human populations). What follows is a redux of my lecture notes from yesterday. I follow pretty closely the topics of Chs. 2-6 of David C. Geary, The Origin of the Mind: Evolution of Brain, Cognition and General Intelligence (Washington, D.C.: APA, 2005). But I also mix in some Deweyan language to take off some of the rough edges in Geary’s theory.
What selective pressures might have caused encephalization?
anticipate unpredictable climate, ecological and social changes within a lifetime
bounded by time (have a hard time thinking beyond the time frame of a human life)
climate is unlikely; but ecology is very likely and then at a later point, social
Uncertainty (Geary: Motivation to Control)
[this is a fundamental idea of the American pragmatists, and is most fully expressed in John Dewey’s Nature and Experience.]
nature of the environment is unpredictability and changeability; organisms then experience the desire to stabilize or create equilibrium
does not seek best possible outcomes, but “good enough” outcomes control outcomes
instability, uncertainty, “problems” = need to control and/or to create certainty
Brains & Uncertainty
individuals who control social and physical environment have advantage
attempts to control are dependent on the brain’s structure and cognition
folk psychology, folk sociology, folk physics, folk biology/ecology
Brain development & evolution
evolutionary development (chains and processes in response to the environment)
brain as a continuum of constrained inherent systems and plastic systems
because the environment consists of two kinds of sensory input
invariant social/ecological conditions across generations (constrained)
variant social/ecological conditions within a lifetime (plastic)
debates about prenatal development, but clearly a mixture of
experience of the fetus
input from firing subcortical neurons
inherently constrained patterns of nueral migration
parts of the brain that deal with the environmental patterns most important for “fitness” are the larges and most active depending on the species. In humans: Visual cortex and hand/finger sensitivity/tough/dexterity
Experience and Brain
postnatal experiences influence the brain’s development
learning, developmental experiences, etc.
experiences have a small to moderate influence on brain structure, but a huge influence on the content of the ‘mind’; scientists say that experience “fine-tunes” the brain; human children actually undergo a process of “pruning” neurons, where through experience, neural connections actually die or atrophy as the child grows up, so that by age 12, a large proportion of the neural connections are actually lost, as the child gains the ability to fit into the environment it is born into (social and ecological). Current research suggests that between the ages of 8 and 18, the base metabolism rate for the brain decreases by as much as 50%!
E.G., folk psychology/sociology
the ability to think about the self
and to process social information about the self
self, facial expressions, language, relationships
kin, categorize people (frontal lobes), in-groups, out-groups
all of these co-evolved to aid the individual to fit into its environment
and control social outcomes
folk systems emerge from
inherent constraints <—> experience
the most plastic modules are those dealing with the most variable input
the function of the developmental period of human children is to enable
nueral, perceptual, cognitive, behavioral systems to the variation within
these domains in their particular environments
Bounded Rationality vs. Conscious Problem Solving
decision making mechanisms in our brain that work automatically in our ecological contexts; guide behavioral decisions based on implicit knowledge
remember, this is not the optimal or best behavior, but the “good enough” behavior
Conscious Problem Solving
humans can overcome their automatic decision-making processes and became aware of the environment and use explicit, conscious problem solving. This is on the side of the variant inputs, and so the bounded-rationality is less effective and perhaps even dangerous, because they are unpredictable and uncertain. Here is the most need for cognitive “control”.
Conscious Problem Solving and the Mind
—inhibit the heuristic-based processing of bounded rationality and form conscious representations of the environment in question
Executive Control & Working Memory
[slave systems: especially processing of auditory and visual information]
Executive Control depends on Attentional Control
attention-driven amplification of certain brain functions, which synchronizes the executive brain function with the automatic/slave systems, and amplifies the work of the latter
prefrontal cortex (attention) also controls sense of self and the ability to “time travel”
being able to sense the self in the environment and to project that self backwards and forwards in time is CRUCIAL to the ability to conscious problem solving.
The EC and WM systems combined allow the brain to form conscious representations of a social or ecological environment and MENTALLY CHANGE THAT REPRESENTATIONS, virtually conducting mental experiments.
This combines with the desire to create stability or equilibrium or certainty in the environment, as human beings exert control over their environments.
Evolution of Problem Solving
the climate is to slow in changing to account for the changes
ecological (food, shelter) and social, however, are
The current theory of what the mind actually IS combines all of the above:
self-awareness combines with mental models to create an “perfect world” wherein the individual is able to control and organize and stabilize the environment, both social and ecological. This is the conscious activity that our minds engage in to begin and motivate the on-going problem solving cycle. Notice that it is always a complex interaction of society and physical world, because survival depends on our adaptation in this complex environment. This ability to conjure a “perfect world” is an advantage evolutionarily when the environment is dominated by highly variant information.