Deductive Reasoning

What is deductive reasoning?

Deductive reasoning is a psychological process that people use to make decisions and solve problems. It’s a cognitive function, meaning it’s a conscious intellectual activity like thinking and understanding. In deductive reasoning, you use general ideas or premises to come to a specific conclusion.

If you’re like most people, you use deductive reasoning daily, without thinking about the process. But deductive reasoning is a complex process that:

• Researchers study to understand how people learn, think and make decisions.
• Healthcare providers like psychologists and neurologists consider when they assess cognitive abilities.
• Employers may evaluate as part of pre-employment testing.

Your ability to use deductive reasoning relies on a healthy brain. Medical conditions and injuries that affect the parts of your brain that drive deductive reasoning may make it hard for you to process information and make decisions.

While healthcare providers can’t restore deductive reasoning, there are treatments that may help reduce the impact of losing some of your ability to use deductive reasoning and help you maintain quality of life.

What are examples of deductive reasoning?

Using deductive reasoning is a bit like using mental building blocks to create a solid structure. In deductive reasoning, your building blocks are ideas or premises you believe to be true. By these using ideas, you develop a conclusion that you also believe is true.

There are many examples of deductive reasoning, but one of the best known comes from Aristotle, considered the father of deductive reasoning. Here’s the process:

1. First premise: All men are mortals.
2. Second premise: Socrates is a man.
3. Conclusion: Therefore, Socrates is a mortal.

A modern example could be:

1. First premise: The overhead light in this room is out.
2. Second premise: The light switch turns on a different overhead light.
3. Conclusion: There’s something wrong with the first overhead light.

How does my brain manage deductive reasoning?

Neuroscientists are still unraveling exactly what goes on in your brain when you use deductive reasoning. But most agree that your frontal lobe in the left hemisphere of your brain plays an active role.

Research shows that different sections of your left frontal lobe support deductive reasoning at separate times. Deductive reasoning happens in stages, with specific sections of your frontal lobe becoming active depending on the specific deductive reasoning task.

What conditions affect the part of my brain that manages deductive reasoning?

There’s a very long list of conditions and factors that may affect your frontal lobe and your ability to use deductive reasoning. Some examples include:

• Alzheimer’s disease and other neurodegenerative disorders.
• Attention-deficit/hyperactivity disorder (ADHD).
• Brain lesions.
• Brain tumors.
• Concussions and other traumatic brain injuries.
• Developmental delay.
• Frontotemporal dementia.
• Genetic conditions (such as Huntington’s disease or Wilson’s disease).
• Intellectual disability.
• Learning disabilities and disorders.
• Lewy body dementia.
• Mental health disorders, including mood disorders.
• Seizures (especially frontal lobe seizures) and seizure-related conditions such as epilepsy.
• Sleep disorders.
• Stroke and transient ischemic attack (TIA).

Does growing older affect deductive reasoning?

Changes in your brain as you get older may affect deductive reasoning. For example, your frontal lobe shrinks as you get older, which may affect cognitive functions like deductive reasoning.

How are conditions that affect deductive reasoning diagnosed?

Healthcare providers may do several tests to diagnose these conditions, including:

• Blood tests.
• Brain MRI.
• Cognitive tests.
• Computed tomography (CT) scan.
• Electroencephalogram (EEG).
• Electromyogram.
• Evoked potentials.
• Neuropsychological testing.
• Positron emission tomography (PET) scan.

What are tests to evaluate deductive reasoning?

Healthcare providers typically rely on neuropsychological testing to evaluate deductive reasoning. Employers, teachers and others may use different aptitude tests.

What are treatments for conditions that may affect deductive reasoning?

Treatments vary depending on the specific condition, but specific treatments may include:

• Cognitive rehabilitation: This treatment focuses on tactics, like using organization strategies, which help you manage day-to-day activities.
• Cognitive behavioral therapy (CBT): This and other treatments like light therapy, help with sleep disorders.
• Medication and psychotherapy: Providers may combine these treatments to help people with mood disorders.
• Occupational therapy: In this treatment, an occupational therapist helps you overcome physical, mental and social challenges.
• Physical therapy: Physical therapy is treatment that helps you improve how your body performs physical movements.
• Speech and language therapy: This treatment involves exercises and other steps that help improve your ability to talk and use language skills.
• Treatment for neurodegenerative disorders: Treatments vary depending on the disorder.

What can I do to maintain my deductive reasoning?

The best way to keep your reasoning skills sharp is to take care of your brain. Here are some lifestyle suggestions that may help:

• Drink in moderation: If you drink beverages containing alcohol, limit drinks to two a day for men and people assigned male at birth (AMAB) and one a day for women and people assigned female at birth (AFAB).
• Eat well: Fill your plate with vegetables, fruits, whole grains, lean protein and healthy fats.
• Exercise your brain: Practicing puzzles, such as jigsaw puzzles, crosswords or word searches, is an easy way to keep your brain engaged.
• Get moving: Consistent exercise is one way to keep your brain in good shape.
• Get your rest: Sleep at least seven to eight hours each night.
• Protect your brain: Use protective gear (like wearing seatbelts when you’re in a vehicle), especially while playing contact sports or on the job.
• Quit smoking: Smoking increases your risk of having an ischemic stroke.