As the child grows, there is no doubt that the age IQ becomes stable. It then brings us to the question of what is IQ? An intelligence quotient is a total score derived from a set of standardized tests or subtests designed to assess human intelligence. IQ scores have been shown to be associated with such factors as nutrition, parental socioeconomic status, morbidity and mortality, parental social status, and perinatal environment.
Three assessments of intellectual performance at each of four developmental periods served as indicators of latent intelligence during infancy (1, 1.5, and 2 years old), preschool (2.5, 3, and 3.5 years old), childhood (6, 7, and 8 years old), and adolescence (12, 15, and 17 years old). Intelligence exhibited a high degree of stability across the four developmental periods.
Further, from infancy to adolescence, the effect of intelligence during earlier periods was completely mediated by intelligence during the adjacent developmental period.
IQ Stability Age
From 6 years old onward, correlations among IQ scores range from moderately strong to strong, suggesting that IQ scores are relatively stable once children reach school age.
Correlations among IQ scores increase as children advance in age with correlations between IQ scores measured 3 years apart. Correlations increased from 0.32 (between IQ scores at 2 and 5 years old) to 0.70 (between IQ scores at 5 and 8 years old), and then to 0.85 (between IQ scores at 9 and 12 years old).
Results also showed a slight tendency for correlations between IQ scores to increase with age. The correlation between IQ scores at 3 and 6 years old was 0.73, the correlation between IQ scores at 5 and 8 years old was 0.79, and the correlation between IQ scores at 9 and 12 years old was 0.81.
Again, the strength of correlations between IQ scores may also be a function of the length of the measured interval. Therefore, to evaluate whether the relations between IQ scores increase with age, it is essential to define a uniform measured time interval.
Only a few studies have investigated the stability of IQ scores from infancy through adolescence because of the challenge to recruit infant participants and then track and assess their intellectual development for over 15 years.
Generally, it’s widely accepted that IQ stabilizes around the age of 6 or 7. Before then, the brain is in a plastic enough state that IQ can actually be increased up to 1 standard deviation but past that age, your IQ, and therefore general intelligence, is relatively stable.
Age by Age: IQ Improvement Clues in Children
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Ages 0-2
Read to your child. Often. Talk to him, using direct and sustained eye contact. Turn off the TV. Don’t buy the “education-based” video games. Love and praise your child. Play music you like for her (it does not have to be classical music). Explain everyday things to him. (Tell her why orange juice can sting a cut on a lip. Tell him why a hot stove must not be touched.)
Praise your young scientist for repeating things over and over. Play peek-a-boo and hide-and-seek. Enforce a healthy diet, and try for organic foods if possible. Use routine, with predictable consequences for behavior. Introduce math concepts. Sing the ABCs. Make sure your baby gets enough sleep.
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Ages 2-7
Child should be exposed to new things-music, sports, subjects, activities. Keep reading aloud to your child, and praise her efforts to read to you. Talk to your child about why people behave as they do. Who makes the rules in society? Why? Buckle down on homework, establishing high expectations for work habits. Extra work (school worksheets during summer) is recommended in reasonable doses. Homework should not be a fight. If it is, talk to school teachers or a child psychologist.
This is the age that learning disorders can start to show. Get a handle on them early. If you have the opposite issue–your child wants to learn more than you can possibly teach–try to connect her to an expert in her field of interest. Perhaps a college professor would be willing to tutor your child for a couple hours on a weekend. Schedule playdates. Continue healthy sleep and diet activities.
At this age, children are scientists. Conduct fun and interesting household projects that help your child explore their world. Play guessing games such as, “I spy”, and “I’m thinking of something…” Do puzzles and card games.
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Children 8-12
Encourage independent reading and books-on-CDs. Enforce healthy sleep and diet. Limit TV and video game time. Be an active participant in your child’s academics, remembering that you are doing him no favors by completing homework for him. Teach work skills, including: organization, time management, scheduling, focus. Praise your child for good report cards, but avoid monetary rewards for them. The goal is to help your child internalize the value of good grades, and not simply work for an external reward.
Listen to teacher’s feedback about any problematic academic or social behaviors. Listen to your child. Encourage her to pursue her intellectual passions (which may not be theoretical physics or advanced mathematical theory). Institute a “family game night,” where you play cards, puzzles, or other games that help build reasoning skills. Introduce your child to newspapers and have easy chats about what is happening in the world. Talk about governments, nationalities, and cultures.
Explain real-life issues like, “why do we keep our money in a bank?” “what should you do if a bully picks on you?” and “why does the guy from the gas company read our meter?”
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Ages 12-18
Children become increasingly independent. The foundation for IQ is already set, but test performance can improve for some children. There is no substitute for attending school regularly, paying attention in class, and doing homework. These are musts. Keep a close watch on your child’s use of electronics. Phones, video games, and computers can interrupt sleep, cause social disruption, and distract children from work.
Help your child link her academic performance to her long term goals. Consider hiring a peer tutor, someone your child can actually tolerate. Help your child continue to build work skills such as organization, time management, avoiding procrastination, and breaking down big assignments into small “do-able” parts.
