Average IQ by Age: How Your Intelligence Compares to People Your Age

Many people wonder whether intelligence changes as we get older. You might ask yourself: Is my IQ normal for my age? Am I smarter than most people my age group?

Understanding average IQ by age can help put your cognitive abilities into perspective and explain why some skills improve over time while others naturally decline. If you want a deeper explanation of how IQ scores are defined and standardized, you can explore our complete guide on what IQ is and how it is measured.

This article breaks down how IQ relates to age, what the average scores look like across life stages, and why comparing yourself to your peers can be more meaningful than comparing yourself to the entire population. For a broader overview, you may also find our detailed analysis of average IQ by age helpful.

Does IQ Change With Age?

IQ tests are carefully designed so that the average score is 100 at every age. This is because IQ is age-adjusted, meaning your score reflects how you perform compared to others in your same age group, not compared to people who are younger or older than you.

In other words, a 20-year-old and a 60-year-old with the same IQ score performed similarly relative to their peers, even though their raw cognitive abilities may differ. This age-norming system is explained further in our breakdown of the IQ scale from low to genius.

However, while the overall IQ score remains standardized across age groups, specific cognitive abilities do change over time. Research in cognitive science and neuroplasticity of the brain shows that some mental skills peak early, while others continue to strengthen with experience.

Psychologists generally divide intelligence into two major components to explain these changes:

• Fluid intelligence – the ability to reason quickly, solve novel problems, recognize patterns, and think abstractly
• Crystallized intelligence – accumulated knowledge, vocabulary, factual understanding, and experience-based skills

Fluid intelligence tends to peak in early adulthood and slowly decline, while crystallized intelligence often grows over time through learning and life experience. This distinction is closely related to concepts such as cognitive flexibility and real-world problem-solving ability.

Average IQ by Age Group

Although IQ scores always average 100, studies of raw cognitive performance reveal clear age-related patterns in how different abilities develop and change across the lifespan. You can also compare how you stack up against others your age in our article Are you smarter than your peers?.

Children and Adolescents (Ages 6–17)

Childhood and adolescence are periods of rapid cognitive growth.

During these years:

• Reasoning ability develops quickly
• Memory capacity expands
• Processing speed improves year by year
• Attention span and problem-solving skills become more refined

By the mid-teen years, many reasoning abilities approach adult levels, even though emotional regulation and executive control are still developing. This is why results from child-focused assessments, such as an IQ test for kids, are always interpreted relative to age.

Average IQ (age-adjusted): ~100

Young Adults (Ages 18–25)

Young adulthood is typically the peak period for fluid intelligence.

People in this age range often show:

• Fast reaction times
• Strong abstract reasoning
• High mental flexibility
• Excellent performance on timed and logic-based tasks

This explains why younger adults often score well on traditional assessments like the International Standard IQ Test.

Average IQ: ~100

Key strengths: Speed, logic, mental flexibility

Adults (Ages 26–40)

In early to mid-adulthood, cognitive performance becomes more balanced.

While raw processing speed may begin to stabilize, adults in this age group benefit from:

• Growing real-world experience
• Improved strategic thinking
• Stronger decision-making skills
• Better integration of knowledge and reasoning

This combination often leads to strong performance in practical and professional contexts, especially in roles where problem-solving aptitude matters more than raw speed.

Average IQ: ~100

Key strengths: Reasoning combined with experience

Middle Age (Ages 41–60)

During middle age, subtle cognitive changes may begin to appear.

Common patterns include:

• A slight decline in processing speed
• Slower reaction times compared to younger adults
• Continued growth in vocabulary and general knowledge

Crystallized intelligence is often very strong at this stage, supporting judgment and long-term planning. This is why many professionals excel despite changes in speed, a topic also discussed in IQ vs critical thinking.

Average IQ: ~100

Key strengths: Knowledge, strategy, decision-making

Older Adults (Ages 60+)

In later adulthood, age-related cognitive changes become more noticeable, but they do not affect all abilities equally.

Older adults may experience:

• Slower reaction times
• Reduced short-term memory efficiency
• Difficulty with highly timed tasks

However, verbal ability and accumulated knowledge often remain strong. Emotional skills may also improve, which aligns with research on emotional intelligence and self-awareness.

Average IQ: ~100

Key strengths: Wisdom, verbal ability, long-term knowledge

Why Everyone’s Average IQ Is 100

If IQ always averages 100 at every age, why does age matter at all?

The answer is simple: IQ is a relative score.

When you take an IQ test, your results are compared only to people in your age group. A 60-year-old and a 20-year-old with the same IQ score did not answer the same questions equally fast or in the same way—but they performed similarly compared to others their age.

This age-norming system allows IQ tests to provide fair and meaningful comparisons across different stages of life.

Are You Smarter Than Your Peers?

To understand where you stand, focus on classifications rather than the number itself. You can explore detailed explanations in our IQ scores guide.

• Below 85 – Below average for your age group
• 85–99 – Average (lower range)
• 100–114 – Average to slightly above
• 115–129 – Above average
• 130+ – Gifted

If your IQ is above 100, you are performing better than at least half of people your age. If your score is 115 or higher, you are clearly above average relative to your peers.

Why Older Adults Often Feel “Less Smart”

Many adults report feeling less intelligent as they age, but this perception is often misleading.

What usually changes is:

• Speed, not intelligence
• Memory recall, not understanding
• Reaction time, not reasoning ability

Older adults may process information more slowly, but they often compensate with:

• Better judgment
• Deeper understanding
• Stronger emotional intelligence
• More effective decision-making strategies

As a result, real-world performance often remains high despite changes in test-based measures.

Can You Improve Cognitive Performance at Any Age?

Yes. Research shows that habits such as regular learning, physical exercise, and mental challenges can help maintain or improve cognitive function. Our article on can IQ be improved explores this in detail.

Helpful strategies include:

• Lifelong learning and regular reading
• Mental challenges such as puzzles, strategy games, and problem-solving tasks
• Regular physical exercise
• Quality sleep and stress management
• Social interaction and meaningful relationships

These behaviors support both fluid and crystallized intelligence across the lifespan.

The Bottom Line

So, are you smarter than your peers?

Your IQ score already answers that question—relative to your age group. IQ does not simply decline as you get older; instead, different cognitive strengths shift over time.

No matter your age:

• An IQ around 100 is normal
• Scores above 115 indicate above-average performance
• Intelligence is broader than any single test score

Understanding average IQ by age allows you to evaluate your abilities fairly and reminds you that intelligence evolves rather than disappears throughout life.