Zombie Foodies: How long does it take to grow a human brain?

Yum. (Nick Koudis/Photodisc/Getty Images)

Check your stereotypes at the door, gentle reader, because not every zombie is an indiscriminate brain gobbler. When there's no more room in Hell (or Whole Foods), zombie foodies will walk the Earth and you better believe they won't be caught dead munching on fast-food grey matter.

To satisfy their unholy cravings, many of the world's more food conscious undead cultivate their own premium, local-grown human brains in backyard nurseries, cranium cellars or Brooklyn rooftop gardens.

But just how long does a ravenous zombie have to wait for a delicious full-grown brain?*

Young Minds Proportionally, human infants pack a rather sizeable brain right from the start. Their minds may be tiny and underdeveloped, but they account for a whopping 15 percent of their total body mass. The adult brain, by comparison, accounts for a mere 2 percent. But don't harvest just yet, undead reader, because the human brain develops rapidly. Why harvest an average newborn's 12-ounce (340-gram) brain when you can hold out for a fully-developed three-pound delicacy (roughly 1360 grams)?

If it continues to develop healthily, the newborn brain will reach 75 percent of its adult size within two years and 90 percent by age six. Additional growth spurts occur throughout childhood development and adolescence. Be sure to nurture your prized brains with education because ages 6-13 show important development in areas devoted to language and spatial relation.

Vintage Brains If you're looking to feed more than one zombie, you might want to harvest by age 21 because after that point brain mass tends to decrease. You will, however, find specimens that continue to develop well past this point with the right environmental or scholarly stimuli. Just consider the delicacy that is the London cab driver: a 2000 study found that parts of the cabbies' brains continued to grow and change as they learned complex routes.

If you're more concerned with taste, however, just remember that brain development involves more than mere increases in mass. Left and right brain integration increases with age and some s

Plus, rapid decrease in brain mass typically doesn't kick in till age 80 or so. So yes, those vintage brains in your cranium cellar have some shelf life.

So there you have it! You can find the Stuff to Blow Your Mind podcast on iTunes, Zune and the RSS feed. And don't forget the free HowStuffWorks Appfor iPhone and Android!

*All the facts after this are legit.

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About the Author: Robert Lamb spent his childhood reading books and staring into the woods — first in Newfoundland, Canada and then in rural Tennessee. There was also a long stretch in which he was terrified of alien abduction. He earned a degree in creative writing. He taught high school and then attended journalism school. He wrote for the smallest of small-town newspapers before finally becoming a full-time science writer and podcaster. He’s currently a senior writer at HowStuffWorks and has co-hosted the science podcast Stuff to Blow Your Mind since its inception in 2010. In his spare time, he enjoys traveling with his wife Bonnie, discussing dinosaurs with his son Bastian and crafting the occasional work of fiction.