Why isn't IQ an average or equal to the parents' IQ? How can a child have an IQ higher than both its parents?

Question

I have never really understood that because it means a child's intelligence is more than the sum of the parts of the people that conceived it.

How can something more be created from its creators.

I am quite sure my question doesn't make complete sense but I hope you get my drift.

2 2 = 4

but if two trailer trash idiots beget a genius how can

2 2 = 6??

How can something be more than the sum of its parts or what made it?

Is it a mystery or is their a scientifuc explanation?

Answer 1

Just like a child can be taller than either of his or her parents, a child can be smarter than either of his or her parents.

Intelligence isn't a matter of a single gene like blood type is: it's the sum of many genetic factors that are not yet understood, as well as influenced by the environment in which a child develops.  

So, for example, a child could luck out and inherit a disproportionate number of "smart genes" from each parent just because of random events during the formation of sperm and eggs, and end up with more total "smart genes" than either parent has.

Alternately, the parents could have quite a few smart genes each, but the environment in which they developped was not up to par, so they never reached their potential. Eg. they could have fetal alcohol syndrome, they could have eaten lead paint chips as small children, they could have grown up in a super un-stimulating environment.  But then their kid manages to escape whatever made their parents dumb, and turns out to be really bright.

Answer 2

No need to even address the IQ potion of the question. Genetics doesn't work the way you describe. Could two short people have a tall kid? Yes, possibly both parents had a recessive gene for tallness...or perhaps both parents were malnourished as children.

And even that is horrifically simplified, suffice it to say that in genetics as well as all sorts of other aspects of reality adding two things together can get you something that is more than the sum of the parts: Chlorine at room temperature is a highly toxic gas, and sodium at room temperature is a metal so highly reactive with water that it must be stored immersed in kerosene or some such...if you consumed either of them you would die a gruesome death. Combined they form salt, which can be consumed quite safely. :)

Interesting question in an odd sort of way though.

Answer 3

Chuck, the whole deal with IQ is that it's a terribly, terribly poor predictor of anything other than extreme outliers, e.g. those with scores below 80 are determined to be challenged and standard IQ tests are worthwhile for such cases.  Or a case, for example, of neurodegenerative disease and/or trauma to the head where a baseline can be compared to a post-treatment test to determine if there's been progress, then IQ tests are helpful in psychometrics.  Otherwise, the only practical significane of IQ testing is to determine correlation with future standardized exams.  Beyond that, it's hardly anything to write home about.

Intelligence is such a difficult concept to find a singular definition for, let alone a consensus that psychology has tons of theories, e.g. "athletic intelligence, musical intelligence, etc." that it's simple too elusive a term to even begin to attempt to study in a rigorous manner in the modern era.

In short, we are largely in the dark with respect to how the human mind operates on a gross level, even though we understand how the neuron works quite well.  The best psychology can do is propose rather "soft" theory and "soft" methodology in performing "soft" studies of "Intelligence."  At some point (hopefully with the unraveling of the human genome) we'll have a better grasp on such things.  Until then we are terribly in the dark with such issues in Neuroscience.  Imaging has been a great tool in helping understand things a little better, but hardly enough to form generalizations.

Basically, the most widely accepted theory in formal Psychology is that "Intelligence" (using a broad definition) has both genetic components and environmental componenents.  It's unclear which is dominant, nor is it possible at this stage to predict much based on parental "IQ" scores.

As a matter of any social relevance, common sense and judgement are fare more important than "IQ" and such simply because there are way too many examples of people who've scored modestly on such exams and then went on to benefit society abundantly.  Using IQ to identify extreme outliers (especially the extreme left of the distribution) is a rather effective tool, and that's fairly accepted as a serious usage of IQ.

Answer 4

In my opinion IQ is not just inherited but it also depends on the environment the child lives in

Answer 5

I think it's more random than that, not if you are intelligent you will create an intellignet offspring. intellect doesn't seem to be heriditery.

Answer 6

This is another example of biology superseding socialization. Wake up feminist. You're living in a state of denial.  

Answer 7

because he isn't smarter?

Answer 8

Perhaps one or both parents had the potential to become geniuses, but weren't encouraged to learn in the first three years of life (important time for brain development.) They could have passed their genes for intelligence on to their child, & provided an environment like the one they never had.

Answer 9

because the child is half the moms chromosomes and half the dads , if he gets the better chromosomes of both parents he will be smarter better looking more successful the whole thing...

thank you senlin you are very kind

Answer 10

Throughout history there have occasionally been people whose behaviour has defied explanation.

Great geniuses may bloom in the muck, great villains can emerge from sheltered boudoirs.

It's one the great mysteries and joys of our species.

Cheers :-)

Answer 11

Tiny Dan has summed it up nicely.  And for the same reason, parents with no musical ability can have children who are musically talented.  Usually, if you go back through the family trees, you will find someone else with musical ability, or in your example, someone with intelligence.  It is not a strict 2 + 2 equation.  More like choose one from column a and one from column b.  

In addition, there is something called regression to the mean.  In a population there is a tendency for outliers to be the exception - so the children of outliers are more likely to be closer to the "average."  This also explains why two very smart people can have children who are more average.

Answer 12

Many geniuses of the past have come from the bottom of society...Newton, Riemann etc. were from poor families.

Talent may be inherited, but genius is a different sort of substance, its out of this world and thats what makes it genius.

Answer 13

Let me put it to you like this:

Schrödinger did not have the type of upbrigning that even 3rd world children have. He is a shining example of where greatness can come from. He had nothing, yet believed in his knowledge. It doesn’t come from school or people; it comes from a thirst for knowledge. To find out anything and everything, to learn all you can in the little time you can. Instead of consuming yourself in the fashionata and the media, knowing and learning are the most important things.

Every brain starts out the same, it just depends on how far a person is willing to push theirs that makes the difference. Look at Hawking, another shining example (third favourite theoretical physicist.)

Answer 14

Well lets start off by saying there are many controversies about IQ and its testing.  It can be up to 10 points off in either direction, especially when testing young children.  This is often due to factors unable to be factored into the testing...the child being tired, hungry, nervous, simply having a bad day, etc.  The test is also said the be biased against lower economic level people as well as minorities based on how it is written.

Intelligence is a combination of both nature (what God gave you) and nurture (what you do or the environment you are in).  The average IQ is between 90 and 110 (though some say 85-115).  An IQ below 80 is considered mentally retarded, the lower you get the worse the retardation...so an IQ of 78 is considered moderately retarded while an IQ of 52 is considered severely retarded.

People tend to be attracted to be like themselves.  A person with an exceptional IQ is most likely not going o marry someone with an average or even low IQ.  Thus increasing the possibility of having a child with an exceptional IQ as well.  The same can be said for low IQs, even talents, such as athletic and musically or artistically inclined.

IQ can be greatly effected by environment, especially while in utero.  This is why there is so much pressure on women to avoid teratogens like alcohol, drugs, caffeine, and a long list of foods with various bacterias (soft cheeses) and mercury (some fish).

While Elenore hit the nail on the head about the thirst for knowledge, she is very wrong when saying every brain starts out the same...it doesn't.  Most child development theorists now agree with this though there were a couple (Locke being the most famous) who once believed children start out as a "blank slate" or more commonly known in psychology as "Tabula rasa" and are solely effected by their environment.  This is now known not to be true.

So if two average people (IQs of 100) have a child with an IQ of 100 and then enrich its environment with activities and possibilities which allow the child to grow to their best possible, the child could have an IQ of 120 by the time they go to kindergarten.  If they plop the kid in front of the TV for 5 years the child's IQ could drop to 85.

Your IQ can also change through out your life, usually being dependent on how much you use and enrich your brain.  I while in school and growing up I was given many many opportunities and encouraged to explore curiosities and what not.  I had a 127 IQ when I was 8.   I do not believe it is as high no because I am not exploring and reading about new things at the same rate I was as a child.  This is also why many very intelligent people can appear not so much after aging.