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Old 12-19-2016, 03:28 PM
md2000 md2000 is offline
Join Date: Feb 2009
Posts: 14,213
Originally Posted by John Mace View Post
I've never hear that "rule of thumb" before. Where does it come from?

At any rate, it doesn't make any sense since a severely malnourished infant could have permanent brain damage and severe reduction in cognitive ability. Same with deprivation of oxygen or exposure to some pathogens.
Then maybe we could consider three factors are relevant - genetics, environmental (i.e. nutrition, diseases, etc.) and stimulation (exposure to language, experiences, puzzles, things which give the brain a workout and develop novel connections between the brain cells).

But yes, if you start with the same 50% brain power as anyone else but completely fail to develop it due to oxygen starvation or severe malnutrition or blunt force trauma - then the person will be in the category of 50% of normal intelligence. IQ of 50 is pretty close to being a rutabaga. If the genes in that case developed brain function enough to keep breathing and heart going, then the genes have done their part. Ability to swallow food and drink would be a bonus - 51%.