Genetic Testing Iq Heritability

The idea of “intelligence” means different things to different people. It could mean a high level of competency in science or math. It could also refer to a person with:

  • an ability to learn new skills or concepts quickly
  • creativity in art or music
  • strong analytical skills
  • above-average mechanical skills
  • above-average reasoning skills
  • the ability to learn a foreign language.

These and many more abilities are all factors of intelligence.

How IQ is Measured

IQ (or “intelligence quotient”) testing is a quantifiable way for scientists to measure intelligence. French psychologist Alfred Binet first launched the idea of IQ in 1904. According to Binet, you could measure someone’s intelligence quotient by dividing his mental age by his chronological age, and then multiplying by 100. For example, a 9-year-old with the mental capabilities of an 11-year-old would have an IQ of 122. A normal child functioning exactly at his age level would have an IQ of 100.

This method is seldom used today, partly because it doesn’t work for adults. A contemporary version of an IQ test compares subjects to a number of their peers. The average IQ is set at 100 and participants are ranked according to that scale.

A typical IQ test evaluates skills in:

  • abstract reasoning
  • common sense
  • factual knowledge
  • language skills
  • short-term memory
  • visual-spatial abilities.

While IQ tests are useful in predicting success in school, they can’t measure intangibles like creativity or people skills — which are also forms of intelligence. Other personality tests, such as the Meyers-Briggs, measure types of intelligence and the way individuals perceive the world.

IQ’s Genetic Link

Scientists are divided over what role, if any, genetics play in a child’s intelligence. Studies on identical and fraternal twins imply that genetics do play an important role in determining IQ.

Identical twins have exactly the same genes, and in most cases, they have comparable IQs. Additionally, identical twins that have been adopted into different families often have similar IQs as adults. Fraternal twins, on the other hand, often have wide differences in their IQs.

Doctors have recently discovered that genetic traits for intelligence may lie in two specific DNA regions. With more research, a genetic test for intelligence may one day be available.

Nature vs. Nurture

Although genes play an important role in revealing intelligence, they don’t work alone. Environmental factors, such as parental neglect, lack of a balanced diet or absence of early mental stimulation can handicap a child’s inherited potential. Most researchers believe that a child can only reach his or her potential in an environment that encourages their abilities.

Parenting a Gifted Child

Parents of intelligent babies often wonder how to provide a stimulating environment for their children. If your child has above-average intelligence, you need to create a home environment that allows that potential to grow. Many children with high IQs struggle with perfectionist tendencies. They are afraid to take risks to avoid failure at all costs.

Parents of exceptional children need to guide them and help them develop a “growth mindset.” This way of thinking encourages the child’s abilities without focusing about perfection. You can help your gifted child achieve this mindset by:

  • encouraging effort instead of praising results
  • providing chances to build small successes and face small failures
  • setting goals stressing improvement
  • stressing personal growth rather than top performance.

Whether or not your child has been classified as “gifted,” there are many things that you can do to encourage their cognitive development. Provide your child with an intellectually stimulating environment and encourage exploration and play.


a2zPsychology (2006). Intelligence. Retrieved November 19, 2008, from the a2zPsychology Web site:

Boulianne, C.M. (2008). Tips for parenting perfectionist gifted children. Retrieved November 20, 2008, from the Suite 101 Web site:

Psychological Testing (n.d.). Intelligence testing. Retrieved November 19, 2008, from the Psychological Testing Web site: