The Human Brain

Cerebrum

Corpus Callosum

Cerebrum

Pituitary

Hypothalamus

“In the most intelligent races, as among the Parisians, there are

a large number of women whose brains are closer in size to those of gorillas than to the most developed male brains. This inferiority is so obvious

that no one can contest it for a moment; only its degree is

worth discussion.

All psychologists who have studied the intelligence of women, as well as poets and novelists, recognize today that they represent the most inferior forms of human evolution

and that they are closer to children and savages than to an adult, civilized man. They excel in

fickleness, inconstancy, absence of thought and logic, and incapacity to

reason.

Without doubt there exist some distinguished women, very

superior to the average man, but they are as exceptional as

the birth of any monstrosity, as, for example, of a gorilla with two

heads; consequently, we may neglect them entirely.” –

Gustave LeBon, 1879Founder of Social Psychology

Morton’s final summary of craqnial capacity by race

German, English, Am 92 sq inSemitic 89Mongolian group 82Malay group 85Peruvian, Mexico 79Barbarous tribes 84Negro group 83Australian aborigian 75

Bean’s Plot

Width of brain

Length of brain

White

black

Gould used more modern methods

• Blind test

• Adjust for body size

• Adjusted for cause of death

• Adjusted for age at death

Mall’s Plot – Steven Jay Gould

Width of Brain

Length of Brain

Neurotransmitter

Synapse

The human brain – Flexible ciruitry

50 billion neurons

(chimps have 5.5 billion)

Each of these neurons can receive messages from 1,000 other neurons

An also send messages to 1,000 other neurons

Brain development after birth

Before birth and for 6 months after birth 500,000 new neurons are produced each minute.

Brain doubles in size from birth to 1 year

Doubles again by age 4 – reaching adult size by 4 or 5.

Ruth Bleier’s Theory of Intelligence

Intelligence is a complex entity of:

brainbehavior mindbody environment

The parts of this complex are inextricable from one another. The parts and the whole are ceaselessly interacting and changing and carry within themselves the entire history of their interactions.

Back to flexibility of circuitry

The functional validity of developing synapses occurs through environmental input as a means by which neurons acquire normal anatomical connections and function.

Different experiences will develop different anatomic connections.

Ruth Bleier

-Genes cannot encode for all the complex behavior for a species that occupies every possible niche

-We learn how we are supposed to be

-Culture – values, beliefs, expectations, conformity become known as:

HUMAN NATURE