by Leah Fontaine
In chapter four, Greg Downey and Daniel H. Lende discuss the human brain and the many theories that talk about how and why humans have evolved differently than other primates. It begins by discussing the correlation between brain and body size in many animals and how humans have a disproportionately large brain compared to the body. While other mammals have developed better systems for eating and reproduction, human's brain size has caused potential problems in both highly necessary features of survival. The disproportionate aspects of our brain doesn't stop at its total size however, and can be seen even in the size of the different parts of our brain especially the neocortex. The chapter goes on to discuss how the connections in the brain create many of the differences we see both physically and that create some of our abilities culturally. Changes in environment can greatly affect the connections that developing brains make and with humans developing so much outside of the womb there are many differences between people. Humans are a very social species which has helped develop the distinctive way that our brains work. Children are dependent on others to take care of them and this long time of dependency gives humans the chance to teach offspring more and provides opportunities for more diversity. Our ability to pass down our knowledge allows us to build on it. This along with our ability to empathize and work with each other has shaped how our brain has developed.
With my background mostly centering around culture and religion, this chapter makes me think more about childrearing and the way that has a lasting impact on all humans. I'm interested in what ways environment and culture can create and change different connections in the brain and how drastic these differences can be especially when looking at those who have experienced trauma or abuse.