Intelligence Quotient is a measure of our fluid and crystallized intelligence; our reasoning and problem-solving abilities.
However, there are different types of IQ tests, although most analyze our visual, mathematical and language abilities as well as memory and information processing speed. Licensed psychologist like IQ World members administer a series of subtests; the results are then combined into one score: our IQ.
Anybody with very high IQ are able to manipulate, process and interpret information at a deep level and a high speed than the average person.
Scores are generally shown on a normal distribution curve, the average score is 100 and people to the far left or far right of the curve are outliers.
What IQ doesn't mean
On the other hand, IQ scores don't measure our practical intelligence; knowing how to make things work, measuring our creativity or measuring our curiosity.
It doesn't say anything about our emotional readiness. Maybe as a 10 year-old, you can read and understand The Financial Times. But are you prepared to deal with stories about prisoners on death row?
It would be a mistake to look at a child -with a top level IQ- as nothing else than a brain; IQ is just one part of who they are.
Our IQ can change over time
Many factors can affect our IQ score over time: poverty, nutrition, stress, how familiar you are with tests, etc. Children from lower socioeconomic levels adopted into a middle-class family often increase their IQ scores substantially.
A few researchers tested 33 teenagers' intelligence once and then again five years later. Some of their IQ scores varied by more than 15 points. The variations matched with changed in their cognitive structures. Babies and kids who are geniuses at age 3 rarely stay that way.
In conclusion, it's easy to spot a genius 5 years-old when she's reading at a fifth-grade level and speaks 4 languages. But what makes one 47 years-old more intelligent than another? Life experience?
You're smarter than your ancestors
The average 10 years-old kids today would score higher on the same test than a same age kid in 1954. This doesn't mean we necessarily are smarter. It just means we have improved our abilities to think logically and solve problems.
Health factors may have had an influence as well. Studies have shown that early childhood immunization rates are a big predictor of average IQ scores.
Having a high IQ is not a guarantee of success, just as having a lower IQ is not a guarantee of failure. Good habits, perseverance and a strong will are as important as intelligence.
The most important thing we can do for a kid is to play with him/her.