He created man in His own image,
In the image of God He created him;
Male and female He created them.
Genesis 1:27
You formed my inward parts; You wove me in my mother's womb.
I will give thanks to You, for I am fearfully and wonderfully made;
Wonderful are Your works, And my soul knows it very well.
My frame was not hidden from You, When I was made in secret,
And skillfully wrought in the depths of the earth;
Your eyes have seen my unformed substance;
And in Your book were all written
The days that were ordained for me,
When as yet there was not one of them.
Psalm 139:13-16
This week I read a great chapter in Recovering Biblical Manhood & Womanhood that described a biological basis for gender-specific behavior. This chapter by Gregg Johnson did an excellent job of using Scripture as the basis for our understanding of biology as he looked at the differences between the sexes. It is because original scientists assumed the authority, sufficiency and reliability of the Scripture that we can extrapolate the hard science studies: physics, chemistry, biology, astronomy, geology, etc. We are created male and female: equal but different for a purpose.
Some great highlights from this chapter essay:
Boys and men have a 6% to 10% higher basal metabolic rate than girls and women.
During metabolism, girls convert more energy into stored fat, while boys convert more energy into muscle and expendable circulating reserves.
Males, on the average, have denser, stronger bones, tendons, and ligaments which allow for heavier work and at age 18 will have 50% more muscle mass (mostly in the upper body) than females.
Males have more sweat glands, larger windpipes and bronchi (in the lungs) and 30% more lung capacity than females.
Women have a thicker layer of subcutaneous fat that acts as insulation and energy reserve. (And we wonder why we have those fat dimples on our thighs?!) And can withstand the cold better and have better energy supply for extraordinary endurance as a result. (So, fat is good - but not too much.)
Men have larger hearts, 10% higher red blood cell counts, higher hemoglobin, higher oxygen-carrying capacity, more vitamin K, and platelets. Their rapid clotting and higher metabolism leads to more rapid healing of wounds and bruises. They also have fewer sensory nerve endings in the skin and higher peripheral pain tolerance.
Women have more stored and circulating white blood cells, more granulocytes and lymphocytes for fighting infection. We produce more antibodies faster and have a more rapid and effective response to infectious invaders. Always a plus. :-)
Males have larger teeth, more salivary glands, and more active gastric glands of the stomach and are more susceptible to ulcers. Their metabolic machinery converts more food to circulating energy and building blocks and less to fat. Circulating blood sugar, cholesterol and amino acids are higher and assimilate food faster. This is great until the body building and high activity years are over and it causes plaque build-up and they become at higher risk for heart attacks, strokes, hypertension, headaches, ringing ears and dizziness.
Women have more trouble eating enough to maintain vitamin and amino acid requirements without putting on fat as well. :-( There is a strong correlation between body fat and fertility.
There are differences present at birth also. Baby girls fix their focus on faces, respond earlier to smells and sounds, voices and touch and vocalize more than boys. They learn to talk sooner and tend to draw people objects. Baby boys orient more to objects, lights, and toys, mobiles and ticking clocks and they learn to draw 3-D images faster. Baby boys more often have hemispheric asymmetry with a smaller left hemisphere in the brain (which continues through adulthood) while girls have a more equal symmetry and have a larger corpus callosum (the part that joins the two brain hemispheres together and helps them to communicate) is larger (that continues through adulthood also).
Because of these brain differences, women will tend to have an easier time multi-tasking and recovering after strokes, although men can learn and re-learn it just as well. It will come more naturally to women whose brains communicate more efficiently across the corpus callosum. It is also because of this connection of the callosum that women assimilate, differentiate and understand multiple inputs of information simultaneously. This is how a woman knows that two different people are speaking at once, the milk in the microwave is finished, the baby is more distressed than normal, the laundry is just starting the spin cycle and the answering machine has a new message - and even more than this also. This ability is what has come to be called, "Women's Intuition" most likely.
These were the parts I considered most helpful.
Read the full essay
here. (Click on view chapter (PDF)).
Read the book for free
online.