The Pleistocene symbol PS is the epoch from 2,586,000 to 9,700 years BC
that spans the world's recent period of repeated glaciations.
The labeling the history of biological and cultural development has a historical foundation that can lead to Sophistry rather than Clarity.
The problem is two fold:
1) Labeling Stages of development by archeological evidence could recognize sequential development before accurate dating methods were available, so investigators developed their own sequential nomenclature (like when they started using copper).
2) Human technological development took place at different times in different areas.
The way these topics are taught often does harm to the overall gestalt formation process. Part of the problem is memorization to pass a test rather than mind expansion by interest and investigation. Fact and label memorization are rewarded but in fact it harms healthy holistic development, for those that are able.
Pragmatically the memorization can make robotically useful behavior in people that even lack healthy early childhood brain development to achieve healthy holistic development as adults
For me, even for teaching by memorizing, it would be far healthier to have an overall holistic approach.
Background - There are two main types of learning approach, simplistically these are:
Arrows represent the focus of attentention.
The basic state of an fetus is serenity. In later stages of pregnancy the serenity is broken mainly by pressure, movement and noise.
Natural birth is traumatic for both mother and child but for a culturally healthy mother her focus in the suffering is on the child. The event is traumatic for the child and the mammalian maternal care for the new born creates a healthy two-way maternal caring bond. The trauma of natural child birth triggers many physiological processes both of physical and behavioral development.
Before abortion many women had started having caesarian section births. This weakening of the mammalian bond led to a weakening of the foundation for growing to higher (altruistic) levels of care. Daycare further weakens the development of ability to form a caring bond an we have a generational increase of autism.
In a child that has a healthy maternal caring bond, the baby is roused from serenity out of some internal need. The need is internal and causes the baby to fuss. The mother responds to the fuss and meets the need so the infant returns to serenity. That is and "IN" foundation of early child development.
For the infant left not responded to or inappropriately responded to the internal focus gets lost.
At first the focus turns to "Out" with screaming and kicking to get attention.
If not responded to for long term the infant goes into distractive repetitive behavior.
This infant stage of life is the period when nerve growth factor is present in certain areas of the brain. After a period the nerve growth factor goes to a different area and past area will never develop to the healthy potential.
The experiment that first demonstrated this was to have different groups of rodents and cover their eyes at birth. Then for different groups take off the blinders at later and later periods. Then let them all mature and analyze the visual cortex.
The results showed that once nerve growth factor was gone the visual cortex did not develop even with stimulation.
Learning in reality is a mix of these two "IN" and "OUT" but in healthy infant development the infant has a sense of control through the maternal nursing bond with their slightest need being responded to.
Those needs are:
3) Response and
4) New Experience.
Given a healthy pregnancy and birth, "nerve growth factor" is present for brain development during the first year after birth. Then with a healthy maternal nursing bond and interaction to give the necessary security and stimulation, the infant feels in control (the "IN" model) and starts to explore within that framework.
Healthy infant world view everything is part of self just like in the womb, the internal needs control the world.
The later ability to grow in levels of empathy is dependent on development in the brain the first year after birth.