PSYC 307 Lecture 7 Neocortex -higher order functions, sensory perceptions, language, complex thoughts -newly evolved part of brain -as brain gets bigger, neocortex gets bigger -neocortex ratio= volume of neocortex/ volume of rest of brain 1) Fruit Diet -more fruit diet, does not predict much 2) Food Extraction -more food extraction techniques -no pattern 3) Social Brain Hypothesis -large groups-> bigger brain -bigger neocortex -humans have highest NR Magic number 150 -largest number beyond which humans start breaking off groups Social Learning -when one model has figured out solution to problem -others copy -rely not on yourself but on the model to figure out solutions
Cultural brain hypothesis -brain involved in loop of social learning and group size -larger groups-more protection-made sense to be in larger groups -led to more cooperation in the groups for collective fitness -large groups-need to keep track of lot of information about more people -bigger brain-made us more efficient at learning -we started to engage in much more social learning -social learning more effective in bigger groups -large groups give more models to choose/learn from Muthukrishna et al -without theory of mind, cannot engage in social learning Ratchet effect -culture always increasing in complexity -e.g. hammer Challenge with bigger groups -too many people from whom you can copy Prestige bias -determines who we choose to learn from -focus more on people who garner attention -young infants are able to discern between models who do and don't get attention 2
-humans, non-human primates have different types of mental capabilities -learning individually which would require a massive brain, which wouldn't be efficient for humans -humans have high neocortex ratios and high EQ Jared Diamond thesis in Guns, Germs, and Steel Proximal Causes -something that has direct and immediate effects -e.g. eating raw and vomiting Distal Cause -initial differences that lead to effects over long periods of time -e.g. vomiting because of biological process passed down by ancestors Papua New Ge 3