Brain Rules by Dr. John Medina
Brain Rule # 11 – Male and female brains are different.
Scientists of both sexes agree that the parts of the brain responsible for
decision-making (front and prefrontal cortex) are different in males and females. They have found that parts of the front and prefrontal cortex are fatter in women than men. Medina asks the question, “Is bigger better?” Further, there are differences in the limbic system which controls emotions and some types of learning. Other differences are found in the amygdala, responsible for emotions and memory. P. 247
The Battle of the Sexes – As early as Aristotle (384-332 BC) and Martin Luther
(1483-1546 AD) there has been a sort of battle between the sexes. Medina quotes
Aristotle as saying that females are a deformity. Further, a quote from Luther
indicates that he believed girls to be weeds growing faster than boys, good crops.
P. 248 In our life time a book, Men are from Mars, Women are from Venus
continues this theme.
Modern research has led to a greater understanding, though we still have much
to learn. Early we observed that mental retardation occurred more often in males
than females. “Many of these pathologies are caused by mutations in any one of
the 24 genes within the X chromosome. As you know, males have no backup X. If
their X gets damaged, they have to live with the consequences. If a female’s X is
damaged, she can often ignore the consequences. This represents to date one of
the strongest pieces of evidence showing the involvement of X chromosomes in
brain function and thus brain behavior.” Mental health providers see similar sex-based differences in their field. P. 249-250
“You have probably heard the term left brain vs. right brain. You may have heard
that this underscores creative vs. analytical people. That’s a folk tale, the
equivalent of saying the left side of a luxury liner is responsible for keeping the
ship afloat, and the right is responsible for making it move through the water.
Both sides are involved in both processes. That doesn’t mean the hemispheres
are equal, however. The right side of the brain tends to remember the gist of an
experience, and the left brain tends to remember the details.” P. 250
Larry Cahill and other researchers have found that “…women recall more
emotional autobiographical events, more rapidly and with greater intensity, than
men do. Women consistently report more vivid memories for emotionally
important events such as a recent argument, a first date, or a vacation. Other
studies show that, under stress, women tend to focus on nurturing their offspring,
while men tend to withdraw.” P. 251
Men and women cement relationships differently. While women “maintain eye
contact, and do a lot of talking” men “rarely face each other directly, preferring
either parallel or oblique angles.” “Doing things physically together is the glue
that holds their relationships intact.” P. 253
Getting the facts straight on emotions is essential for teachers and business
professionals. The need to know:
1. “Emotions are useful. They make the brains pay attention.
2. Men and women process certain emotions differently.
3. The differences are a product of complex interactions between nature
and nurture.” P. 256
One teacher noticed a big gap in the performance of her students – girls did much better in the language arts and the boys better in math and science. By allowing the girls to learn math and science separately, the gap disappeared. Though further study is necessary, co-ed classes may hinder learning for all. In business this idea could also help productivity. P. 256-258
Dr. John Medina’s summary of Rule # 11: Male and female brains are different.
· “The X chromosome that males have one of and females have two of –
though one acts as a backup – is a cognitive ‘hot spot,’ carrying an
unusually large percentage of genes involved in brain manufacture.
· Women are genetically more complex, because the active X chromosomes
in their cells are a mix of Mom’s and Dad’s. Men’s X chromosomes all
come from Mom, and their Y chromosome carries less than 100 genes,
compared with about 1,500 for the X chromosome.
· Men’s and women’s brains are different structurally and biochemically –
men have a bigger amygdala and produce serotonin faster, for example –
but we don’t know if those differences have significance.
· Men and women respond differently to acute stress: Women activate the
left hemisphere’s amygdala and remember the emotional details. Men use
the right amygdala and get the gist.” P. 260