Fluid vs. Crystallized Intelligence

Table of ContentsView AllTable of ContentsFluid IntelligenceCrystallized IntelligenceDifferencesChangesIntelligence TestsImproving IntelligenceHow They Work Together

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Table of Contents

Fluid Intelligence

Crystallized Intelligence

Differences

Changes

Intelligence Tests

Improving Intelligence

How They Work Together

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Fluid vs. crystallized intelligence are two types of intelligence that influence your ability to function effectively in your daily life. Fluid intelligence involves the ability to reason and think flexibly, whereas crystallized intelligence refers to the accumulation of knowledge, facts, and skills acquired throughout life.

Some people say that intelligence starts to decline as people age. However, research suggests that while fluid intelligence begins to decrease after adolescence, crystallized intelligence continues to increase throughout adulthood.

Verywell / Emily Roberts

Cattell defined fluid intelligence as “the ability to perceive relationships independent of previous specific practice or instruction concerning those relationships.”

Fluid intelligence involves being able to think and reason abstractly and solve problems. This ability is considered independent of learning, experience, and education.

When you encounter an entirely new problem that cannot be solved with your existing knowledge, you must rely on fluid intelligence to solve it.

Fluid intelligence examples include:

Fluid intelligence tends to decline during late adulthood. Certain cognitive skills associated with fluid intelligence also tend to decline as people reach later adulthood.

Crystallized intelligence involves knowledge that comes from prior learning and past experiences. In other words, it’s all of the facts, figures, and other accumulated knowledge that you’ve acquired over the course of your life.

Crystallized intelligence is based upon facts and rooted in experiences. As we age and accumulate new knowledge and understanding, crystallized intelligence becomes stronger.

Crystallized intelligence examples include:

So, what can you do to increase your crystallized intelligence? As you might expect, thistype of intelligencetends to increase with age.The more learning and experience you have, the more you build up your crystallized intelligence.

Differences Between Fluid and Crystallized Intelligence

Fluid and crystallized intelligence are very important but serve different purposes. Think of them a bit like two sides of the same coin. While they are vital for your ability to function and interrelated in many ways, there are several ways in which each intelligence type is distinct.

Fluid IntelligenceRefers to current abilityInvolves openness to learning new thingsDecreases with ageCrystallized IntelligenceRefers to prior learningInvolves recalling specific factsIncreases with age

Fluid IntelligenceRefers to current abilityInvolves openness to learning new thingsDecreases with age

Refers to current ability

Involves openness to learning new things

Decreases with age

Crystallized IntelligenceRefers to prior learningInvolves recalling specific factsIncreases with age

Refers to prior learning

Involves recalling specific facts

Increases with age

Both fluid and crystallized intelligence are factors that Cattell referred to asgeneral intelligence.General intelligence is your broad cognitive capacity. It is often referred to as g-factor or IQ.

While fluid intelligence involves our current ability to reason and deal with complex information around us, crystallized intelligence involves learning, knowledge, and skills that are acquired over a lifetime.

Despite its name, crystallized intelligence is not a form of fluid intelligence that has become “crystallized.” Instead, the two facets of general intelligence are considered separate and distinct.

Changes in Fluid vs. Crystallized Intelligence

Fluid and crystallized intelligence tends to change throughout life, with certainmental abilities peaking at different points. Young people may think more quickly, but older people have a larger bank of general knowledge.

In general, fluid intelligence tends to be sharpest in early adulthood, while crystallized intelligence continues to grow through life.

Fluid intelligence has long been believed to peak quite early in life, but some research suggests that some aspects of fluid intelligence may peak as late as age 40.Crystallized intelligence does tend to peak later in life, hitting its apex around age 60 or 70.

Some things to remember about fluid and crystallized intelligence:

Fluid and Crystallized Intelligence Tests

Intelligence testing has been the subject of a lot of debate and interest in psychology, yet many experts believe that standard IQ tests don’t fully capture a person’s fluid and crystallized intelligence levels.

Tests that measure fluid intelligence:

Tests that measure crystallized intelligence:

How to Improve Fluid and Crystallized Intelligence

More recently, evidence has found that it is possible to improve aspects of fluid intelligence, such as processing speed. How? It involves using brain training, also known as cognitive training, to help sharpen your skills.

The researchers discovered, however, that the training also increased unrelated cognitive skills, including the ability to reason and solve new problems independently of previously acquired knowledge.

In essence, with training, a person may engage the abstraction of thoughts and ideas as readily as applying knowledge-based reasoning.

How to Improve Fluid IntelligenceChallenge yourselfMix up your routineThink creativelySocialize regularly

How to Improve Fluid Intelligence

Challenge yourselfMix up your routineThink creativelySocialize regularly

Crystallized intelligence, on the other hand, is something that can be improved through learning. The more accumulated knowledge you have, the more crystallized intelligence you will possess.

How to Improve Crystallized IntelligenceLearn a new languageLearn a new skillTake a classRead books

How to Improve Crystallized Intelligence

Learn a new languageLearn a new skillTake a classRead books

Seeking new knowledge helps build your crystallized intelligence over time, but challenging yourself with new experiences can improve your fluid intelligence as well.

How Fluid and Crystallized Intelligence Work Together

Which type of intelligence is more important? The reality is that both types of intelligence are equally important in everyday life.

For example, when taking apsychology exam, you might need to rely on fluid intelligence to come up with a strategy to solve a statistics problem. At the same time, you must also employ crystallized intelligence to recall the exact formulas you need to use.

Though each is a distinct type of intelligence, fluid and crystallized intelligence are intertwined. We use our fluid intelligence as we learn new things, and it is through learning new things that we acquire more crystallized intelligence.

By using fluid intelligence to reason andthink about problems, information can be transferred to long-term memory and become part of crystallized intelligence.

Takeaways

Study participants usually engage in intensive and difficult brain training tasks over relatively short periods of time. This doesn’t mean the same techniques can’t be applied to your own life. The principles are the same.

Seek out new challenges. Gains in intelligence don’t come from sticking to the same old routines. Keep exploring new things in life and keep learning new things. Tackle learning a new language. Take piano lessons. Visit a new country and learn about the people and culture.

All of these types of activities keep your brain engaged, challenged, and focused on learning new things in new ways.

How Genetics and Environment Influence Intelligence

20 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Doucet GE, Hamlin N, Kruse JA, Taylor BK, Poirel N.Link between fluid/crystallized intelligence and global/local visual abilities across adulthood.Conscious Cogn. 2022;106:103429. doi:10.1016/j.concog.2022.103429Brown RE.Hebb and Cattell: The genesis of the theory of fluid and crystallized intelligence.Front Hum Neurosci. 2016;10:606. doi:10.3389/fnhum.2016.00606Kievit RA, Davis SW, Griffiths J, Correia MM, Cam-can, Henson RN.A watershed model of individual differences in fluid intelligence.Neuropsychologia. 2016;91:186-198. doi:10.1016/j.neuropsychologia.2016.08.008Horn JL, Cattell RB.Age differences in fluid and crystallized intelligence.Acta Psychologica. 1967;26:107-129. doi:10.1016/0001-6918(67)90011-xGhisletta P, Rabbitt P, Lunn M, Lindenberger U.Two thirds of the age-based changes in fluid and crystallized intelligence, perceptual speed, and memory in adulthood are shared.Intelligence. 2012;40(3):260-268. doi:10.1016/j.intell.2012.02.008Unsworth N, Fukuda K, Awh E, Vogel EK.Working memory and fluid intelligence: Capacity, attention control, and secondary memory retrieval.Cognitive Psychology.2014;71:1-26. doi:10.1016/j.cogpsych.2014.01.003Horn JL.Organization of abilities and the development of intelligence.Psychological Review.1968;75(3):242-259. doi:10.1037/h0025662Rabbitt P.Crystallized intelligence. In: Pachana NA, ed.Encyclopedia of Geropsychology. Springer Singapore; 2016:1-4. doi:10.1007/978-981-287-080-3_147-1Barbey AK.Network neuroscience theory of human intelligence.Trends Cogn Sci (Regul Ed). 2018;22(1):8-20. doi:10.1016/j.tics.2017.10.001Brown RE.Hebb and Cattell: The Genesis of the Theory of Fluid and Crystallized Intelligence.Front Hum Neurosci.2016;10:606. doi:10.3389/fnhum.2016.00606Hartshorne JK, Germine LT.When does cognitive functioning peak? The asynchronous rise and fall of different cognitive abilities across the life span.Psychol Sci.2015;26(4):433-43. doi:10.1177/0956797614567339Happé F.Crystallized intelligence.Encyclopedia of Autism Spectrum Disorders.doi:10.1007/978-1-4419-1698-3_1723Holden LR, Tanenbaum GJ.Modern assessments of intelligence must be fair and equitable.J Intell. 2023;11(6):126. doi:10.3390/jintelligence11060126Gomez R, Vance A, Watson SD.Structure of the Wechsler Intelligence Scale for Children - Fourth edition in a group of children with ADHD.Front Psychol. 2016;7:737. doi:10.3389/fpsyg.2016.00737Hidese S, Ota M, Matsuo J, et al.Correlation between the Wechsler Adult Intelligence Scale- 3rd edition metrics and brain structure in healthy individuals: A whole-brain magnetic resonance imaging study.Front Hum Neurosci.2020;14. doi:10.3389/fnhum.2020.00211Haier RJ.Increased intelligence is a myth (so far).Front Syst Neurosci. 2014;8:34. doi:10.3389/fnsys.2014.00034Bonnechère B, Klass M, Langley C, Sahakian BJ.Brain training using cognitive apps can improve cognitive performance and processing speed in older adults.Sci Rep. 2021;11(1):12313. doi:10.1038/s41598-021-91867-zAu J, Sheehan E, Tsai N, Duncan GJ, Buschkuehl M, Jaeggi SM.Improving fluid intelligence with training on working memory: a meta-analysis.Psychon Bull Rev.2015;22(2):366-77. doi:10.3758/s13423-014-0699-xStankov L, Lee J.We can boost IQ: Revisiting Kvashchev’s experiment.J Intell. 2020;8(4):41. doi:10.3390/jintelligence8040041Cohn-Schwartz E.Pathways from social activities to cognitive functioning: The role of physical activity and mental health.Innov Aging. 2020;4(3):igaa015. doi:10.1093/geroni/igaa015Additional ReadingHorn, J. and Cattell, R.Age differences in fluid and crystallized intelligence.Acta Psychologica.1967;26,107-129. doi:10.1016/0001-6918(67)90011-X

20 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Doucet GE, Hamlin N, Kruse JA, Taylor BK, Poirel N.Link between fluid/crystallized intelligence and global/local visual abilities across adulthood.Conscious Cogn. 2022;106:103429. doi:10.1016/j.concog.2022.103429Brown RE.Hebb and Cattell: The genesis of the theory of fluid and crystallized intelligence.Front Hum Neurosci. 2016;10:606. doi:10.3389/fnhum.2016.00606Kievit RA, Davis SW, Griffiths J, Correia MM, Cam-can, Henson RN.A watershed model of individual differences in fluid intelligence.Neuropsychologia. 2016;91:186-198. doi:10.1016/j.neuropsychologia.2016.08.008Horn JL, Cattell RB.Age differences in fluid and crystallized intelligence.Acta Psychologica. 1967;26:107-129. doi:10.1016/0001-6918(67)90011-xGhisletta P, Rabbitt P, Lunn M, Lindenberger U.Two thirds of the age-based changes in fluid and crystallized intelligence, perceptual speed, and memory in adulthood are shared.Intelligence. 2012;40(3):260-268. doi:10.1016/j.intell.2012.02.008Unsworth N, Fukuda K, Awh E, Vogel EK.Working memory and fluid intelligence: Capacity, attention control, and secondary memory retrieval.Cognitive Psychology.2014;71:1-26. doi:10.1016/j.cogpsych.2014.01.003Horn JL.Organization of abilities and the development of intelligence.Psychological Review.1968;75(3):242-259. doi:10.1037/h0025662Rabbitt P.Crystallized intelligence. In: Pachana NA, ed.Encyclopedia of Geropsychology. Springer Singapore; 2016:1-4. doi:10.1007/978-981-287-080-3_147-1Barbey AK.Network neuroscience theory of human intelligence.Trends Cogn Sci (Regul Ed). 2018;22(1):8-20. doi:10.1016/j.tics.2017.10.001Brown RE.Hebb and Cattell: The Genesis of the Theory of Fluid and Crystallized Intelligence.Front Hum Neurosci.2016;10:606. doi:10.3389/fnhum.2016.00606Hartshorne JK, Germine LT.When does cognitive functioning peak? The asynchronous rise and fall of different cognitive abilities across the life span.Psychol Sci.2015;26(4):433-43. doi:10.1177/0956797614567339Happé F.Crystallized intelligence.Encyclopedia of Autism Spectrum Disorders.doi:10.1007/978-1-4419-1698-3_1723Holden LR, Tanenbaum GJ.Modern assessments of intelligence must be fair and equitable.J Intell. 2023;11(6):126. doi:10.3390/jintelligence11060126Gomez R, Vance A, Watson SD.Structure of the Wechsler Intelligence Scale for Children - Fourth edition in a group of children with ADHD.Front Psychol. 2016;7:737. doi:10.3389/fpsyg.2016.00737Hidese S, Ota M, Matsuo J, et al.Correlation between the Wechsler Adult Intelligence Scale- 3rd edition metrics and brain structure in healthy individuals: A whole-brain magnetic resonance imaging study.Front Hum Neurosci.2020;14. doi:10.3389/fnhum.2020.00211Haier RJ.Increased intelligence is a myth (so far).Front Syst Neurosci. 2014;8:34. doi:10.3389/fnsys.2014.00034Bonnechère B, Klass M, Langley C, Sahakian BJ.Brain training using cognitive apps can improve cognitive performance and processing speed in older adults.Sci Rep. 2021;11(1):12313. doi:10.1038/s41598-021-91867-zAu J, Sheehan E, Tsai N, Duncan GJ, Buschkuehl M, Jaeggi SM.Improving fluid intelligence with training on working memory: a meta-analysis.Psychon Bull Rev.2015;22(2):366-77. doi:10.3758/s13423-014-0699-xStankov L, Lee J.We can boost IQ: Revisiting Kvashchev’s experiment.J Intell. 2020;8(4):41. doi:10.3390/jintelligence8040041Cohn-Schwartz E.Pathways from social activities to cognitive functioning: The role of physical activity and mental health.Innov Aging. 2020;4(3):igaa015. doi:10.1093/geroni/igaa015Additional ReadingHorn, J. and Cattell, R.Age differences in fluid and crystallized intelligence.Acta Psychologica.1967;26,107-129. doi:10.1016/0001-6918(67)90011-X

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Doucet GE, Hamlin N, Kruse JA, Taylor BK, Poirel N.Link between fluid/crystallized intelligence and global/local visual abilities across adulthood.Conscious Cogn. 2022;106:103429. doi:10.1016/j.concog.2022.103429Brown RE.Hebb and Cattell: The genesis of the theory of fluid and crystallized intelligence.Front Hum Neurosci. 2016;10:606. doi:10.3389/fnhum.2016.00606Kievit RA, Davis SW, Griffiths J, Correia MM, Cam-can, Henson RN.A watershed model of individual differences in fluid intelligence.Neuropsychologia. 2016;91:186-198. doi:10.1016/j.neuropsychologia.2016.08.008Horn JL, Cattell RB.Age differences in fluid and crystallized intelligence.Acta Psychologica. 1967;26:107-129. doi:10.1016/0001-6918(67)90011-xGhisletta P, Rabbitt P, Lunn M, Lindenberger U.Two thirds of the age-based changes in fluid and crystallized intelligence, perceptual speed, and memory in adulthood are shared.Intelligence. 2012;40(3):260-268. doi:10.1016/j.intell.2012.02.008Unsworth N, Fukuda K, Awh E, Vogel EK.Working memory and fluid intelligence: Capacity, attention control, and secondary memory retrieval.Cognitive Psychology.2014;71:1-26. doi:10.1016/j.cogpsych.2014.01.003Horn JL.Organization of abilities and the development of intelligence.Psychological Review.1968;75(3):242-259. doi:10.1037/h0025662Rabbitt P.Crystallized intelligence. In: Pachana NA, ed.Encyclopedia of Geropsychology. Springer Singapore; 2016:1-4. doi:10.1007/978-981-287-080-3_147-1Barbey AK.Network neuroscience theory of human intelligence.Trends Cogn Sci (Regul Ed). 2018;22(1):8-20. doi:10.1016/j.tics.2017.10.001Brown RE.Hebb and Cattell: The Genesis of the Theory of Fluid and Crystallized Intelligence.Front Hum Neurosci.2016;10:606. doi:10.3389/fnhum.2016.00606Hartshorne JK, Germine LT.When does cognitive functioning peak? The asynchronous rise and fall of different cognitive abilities across the life span.Psychol Sci.2015;26(4):433-43. doi:10.1177/0956797614567339Happé F.Crystallized intelligence.Encyclopedia of Autism Spectrum Disorders.doi:10.1007/978-1-4419-1698-3_1723Holden LR, Tanenbaum GJ.Modern assessments of intelligence must be fair and equitable.J Intell. 2023;11(6):126. doi:10.3390/jintelligence11060126Gomez R, Vance A, Watson SD.Structure of the Wechsler Intelligence Scale for Children - Fourth edition in a group of children with ADHD.Front Psychol. 2016;7:737. doi:10.3389/fpsyg.2016.00737Hidese S, Ota M, Matsuo J, et al.Correlation between the Wechsler Adult Intelligence Scale- 3rd edition metrics and brain structure in healthy individuals: A whole-brain magnetic resonance imaging study.Front Hum Neurosci.2020;14. doi:10.3389/fnhum.2020.00211Haier RJ.Increased intelligence is a myth (so far).Front Syst Neurosci. 2014;8:34. doi:10.3389/fnsys.2014.00034Bonnechère B, Klass M, Langley C, Sahakian BJ.Brain training using cognitive apps can improve cognitive performance and processing speed in older adults.Sci Rep. 2021;11(1):12313. doi:10.1038/s41598-021-91867-zAu J, Sheehan E, Tsai N, Duncan GJ, Buschkuehl M, Jaeggi SM.Improving fluid intelligence with training on working memory: a meta-analysis.Psychon Bull Rev.2015;22(2):366-77. doi:10.3758/s13423-014-0699-xStankov L, Lee J.We can boost IQ: Revisiting Kvashchev’s experiment.J Intell. 2020;8(4):41. doi:10.3390/jintelligence8040041Cohn-Schwartz E.Pathways from social activities to cognitive functioning: The role of physical activity and mental health.Innov Aging. 2020;4(3):igaa015. doi:10.1093/geroni/igaa015

Doucet GE, Hamlin N, Kruse JA, Taylor BK, Poirel N.Link between fluid/crystallized intelligence and global/local visual abilities across adulthood.Conscious Cogn. 2022;106:103429. doi:10.1016/j.concog.2022.103429

Brown RE.Hebb and Cattell: The genesis of the theory of fluid and crystallized intelligence.Front Hum Neurosci. 2016;10:606. doi:10.3389/fnhum.2016.00606

Kievit RA, Davis SW, Griffiths J, Correia MM, Cam-can, Henson RN.A watershed model of individual differences in fluid intelligence.Neuropsychologia. 2016;91:186-198. doi:10.1016/j.neuropsychologia.2016.08.008

Horn JL, Cattell RB.Age differences in fluid and crystallized intelligence.Acta Psychologica. 1967;26:107-129. doi:10.1016/0001-6918(67)90011-x

Ghisletta P, Rabbitt P, Lunn M, Lindenberger U.Two thirds of the age-based changes in fluid and crystallized intelligence, perceptual speed, and memory in adulthood are shared.Intelligence. 2012;40(3):260-268. doi:10.1016/j.intell.2012.02.008

Unsworth N, Fukuda K, Awh E, Vogel EK.Working memory and fluid intelligence: Capacity, attention control, and secondary memory retrieval.Cognitive Psychology.2014;71:1-26. doi:10.1016/j.cogpsych.2014.01.003

Horn JL.Organization of abilities and the development of intelligence.Psychological Review.1968;75(3):242-259. doi:10.1037/h0025662

Rabbitt P.Crystallized intelligence. In: Pachana NA, ed.Encyclopedia of Geropsychology. Springer Singapore; 2016:1-4. doi:10.1007/978-981-287-080-3_147-1

Barbey AK.Network neuroscience theory of human intelligence.Trends Cogn Sci (Regul Ed). 2018;22(1):8-20. doi:10.1016/j.tics.2017.10.001

Brown RE.Hebb and Cattell: The Genesis of the Theory of Fluid and Crystallized Intelligence.Front Hum Neurosci.2016;10:606. doi:10.3389/fnhum.2016.00606

Hartshorne JK, Germine LT.When does cognitive functioning peak? The asynchronous rise and fall of different cognitive abilities across the life span.Psychol Sci.2015;26(4):433-43. doi:10.1177/0956797614567339

Happé F.Crystallized intelligence.Encyclopedia of Autism Spectrum Disorders.doi:10.1007/978-1-4419-1698-3_1723

Holden LR, Tanenbaum GJ.Modern assessments of intelligence must be fair and equitable.J Intell. 2023;11(6):126. doi:10.3390/jintelligence11060126

Gomez R, Vance A, Watson SD.Structure of the Wechsler Intelligence Scale for Children - Fourth edition in a group of children with ADHD.Front Psychol. 2016;7:737. doi:10.3389/fpsyg.2016.00737

Hidese S, Ota M, Matsuo J, et al.Correlation between the Wechsler Adult Intelligence Scale- 3rd edition metrics and brain structure in healthy individuals: A whole-brain magnetic resonance imaging study.Front Hum Neurosci.2020;14. doi:10.3389/fnhum.2020.00211

Haier RJ.Increased intelligence is a myth (so far).Front Syst Neurosci. 2014;8:34. doi:10.3389/fnsys.2014.00034

Bonnechère B, Klass M, Langley C, Sahakian BJ.Brain training using cognitive apps can improve cognitive performance and processing speed in older adults.Sci Rep. 2021;11(1):12313. doi:10.1038/s41598-021-91867-z

Au J, Sheehan E, Tsai N, Duncan GJ, Buschkuehl M, Jaeggi SM.Improving fluid intelligence with training on working memory: a meta-analysis.Psychon Bull Rev.2015;22(2):366-77. doi:10.3758/s13423-014-0699-x

Stankov L, Lee J.We can boost IQ: Revisiting Kvashchev’s experiment.J Intell. 2020;8(4):41. doi:10.3390/jintelligence8040041

Cohn-Schwartz E.Pathways from social activities to cognitive functioning: The role of physical activity and mental health.Innov Aging. 2020;4(3):igaa015. doi:10.1093/geroni/igaa015

Horn, J. and Cattell, R.Age differences in fluid and crystallized intelligence.Acta Psychologica.1967;26,107-129. doi:10.1016/0001-6918(67)90011-X

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