You are misreading the graphic you misposted. Here's the graphic you meant, right? (Fortunately, mastery of HTML is not a valid proxy for IQ).
If you look at that graph, which looks like it came originally from a newspaper, you'll see that 84 IQ means that 16% of the people are at that point or lower (and by definition, then, over 80% are higher. (That both numbers, the IQ and the inverse of the percentile, are 84, is just a coincidence; percentiles are relaitive measures and IQ is absolute).
The midpoint of the graph - 50th percentile -- is a relative measure, too. Half of the group represented on the graph are above and half are below. This point, the median, is the important point that people usually mean when they talk about average. Psychometricians often divide populations into fifths or quintiles; to the extent there's an "average range," it's that center quintile; the 20% that sits in the middle, or about 90-109. By using the lines on this graph, you're defining "average" as "everybody between the top 16% and the bottom 16%," or 68% of the population.
That is, to say the least, a non-standard definition of average. WHat the lines on the chart actually show is one standard deviation from the mean, and what it bounds is probably more accurately called "normal" than "average."
There are some other ways to define the "average" group but none of them encompasses more than 2/3 of the population. Some are brights, some are dulls.
Consider the life choices that an 84IQ individual can make. The professions are out; even college is out (absent luck with athletic ability or affirmative action; and either way, the student will find himself in bottom-tier classes). The armed services are probably out (Only in rare circumstances will recruits from the bottom 16% be taken).
This doesn't mean one can't be a good and productive, even admirable, person, at IQ 84; and it doesn't mean that our society can neglect people functioning at that level. that 16% adds up to almost fifty million of us!
And while there's a lot of evidence that IQ correlates with behaviours, there's no evidence I know of that IQ correlates with worthy character. (I'm not sure how you'd measure that).
In closing, let me at least offer you an explanation of IQ that seems unbiased at first skim, and that definitely offers a much more detailed and accurate example of the graph you posted. I hope you find it informative.
d.o.l.
Criminal Number 18F
My daughter has a low average IQ, and she will definitely be going to college.
My daughter is already doing algebra, and I know she will be able to master all of the math needed to get a degree in at least accounting.
I was good at math (I have a degree in computer science), and she is better than me. She already writes better than I do.
However, she has severe short term memory problems and speech problems. Thank God, she can hire someone to take notes for her in college. I'm hoping by the time she gets to college she'll be able to record the lectures and then just have the computer format into a document she can read.
If you met my daughter, you would not think she was dull.
My 10 year old daughter currently is learning Spanish. She can't say the Spanish words, but she can read them and she can tell what the English word is.