You May Not Know This


2014-0117 empty-toothpaste-tubeThe inspiration for this post came from an article titled “10 Things You Didn’t Know About the Brain” written by Stephanie Pappas, LiveScience Senior Writer, and published by LiveScience.  I did not include the entire article in this post, but there is a link to the Pappas article in the Credits section at the bottom of this post.

In her article, Pappas cites the following facts:

  • The average adult brain weighs just under 3 pounds (between 1.3 and 1.4 kilograms).
  • Some neurosurgeons describe the texture of a living brain as that of toothpaste, but according to neurosurgeon Katrina Firlik, the brain “doesn’t spread like toothpaste. It doesn’t adhere to your fingers the way toothpaste does,” Firlik writes in her memoir, “Another Day in the Frontal Lobe: A Brain Surgeon Exposes Life on the Inside” (Random House, 2006). “Tofu — the soft variety — may be a more accurate comparison.”
  • Approximately 80 percent of the contents of your cranium is brain, while 10% is blood and 10% is cerebrospinal fluid. If you were to blend up all of that brain, blood and fluid, it would come to about 1.7 liters, or not quite enough to fill a 2-liter soda bottle.
  • Brain size doesn’t directly correlate with intellect, so there’s no evidence that ancient man [which, in general, had a larger brain than we have today] was brainier than humans of today.
  • The modern brain is an energy hog. The organ accounts for about 2 percent of body weight, but it uses about 20 percent of the oxygen in our blood and 25 percent of the glucose (sugars) circulating in our bloodstream, according to the American College of Neuropsychopharmacology.
  • What’s the secret to our species’ smarts? The answer may be wrinkles. The surface of the human brain is convoluted by deep fissures, smaller grooves called sulci, and ridges called gyri. This surface is called the cerebral cortex and is home to about 100 billion neurons, or nerve cells. The folded, meandering surface allows the brain to pack in more surface area — and thus, more processing power — into the limited confines of the skull.
  • The old saying that we use just 10 percent of our brainpower isn’t true, but we now know neurons make up just 10 percent of our brain cells.
  • Scientific wisdom once held that when you hit adulthood, your brain lost all ability to form new neural connections. This ability, called plasticity, was thought to be confined to infancy and childhood. Later studies found more evidence of human neurons making new connections into adulthood; meanwhile, research on meditation showed that intense mental training can change both the structure and function of the brain.
  • Popular culture tells us that women and men’s brains are just different. It’s true that male and female hormones affect brain development differently, and imaging studies have found brain differences in the ways women and men feel pain, make social decisions and cope with stress. The extent to which these differences are genetic versus shaped by experience — the old nature-versus-nurture debate — is unknown.
  • But for the most part, male and female brains (and brainpower) are similar. A 2005 American Psychologist analysis of research on gender differences found that in 78 percent of gender differences reported in other studies, the effect of gender on the behavior was in the small or close-to-zero range. And recent studies have debunked myths about the genders’ divergent abilities. A study published in the January 2010 Psychological Bulletin looked at almost half a million boys and girls from 69 countries and found no overall gap in math ability. Focusing on our differences may make for catchy book titles, but in neuroscience, nothing is ever that simple.

Call to Action

If you know any debunked myths or easy-to-understand facts about brains, please share the information with the other readers. Be sure to include the source and supporting text in the comment field below this post.


Thanks to Stephanie Pappas whose article was the inspiration for this post; Live Science (@livescience, Facebook and Google+) which published the Pappas article; and all the people who, directly or indirectly, made it possible for me to use the picture and text in this post.


  1. I’m writing from Ontario, CANADA (cheering for USA-Women’s Hockey team at present!) According to GOOGLE maps, I am 4 053km from Los Angeles. According to the Ontario Brain Institute (see URL below), by the time we reach adulthood, our heads each contain up to 176,000 kilometers of wiring.So, for my American friends, just think it as flying from L.A. to Toronto, and BACK, 21 times … does that not excite/amaze you all? ALL that wiring is in our heads!?!?!

    Ontario Brain Institute (

    1. Barbara, I was not aware of that fact. I think it is amazing how our brains are built, what they accomplish, and how resilient they can be when treated well.

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