Deductive Reasoning: What It Is, Why It’s Important, and Examples

Deductive reasoning is the act of coming to a conclusion based on information that is assumed to be generally true. Deductive reasoning, also referred to as deductive logic or top-down thinking, is a type of logical thinking that’s used in various industries and is often sought after by employers in new talent. The following is a formula often used in deduction: If A = B and B = C, then in most cases A = C. So, for example, if traffic gets bad starting at 5 p.m. and you leave the office at 5 p.m., it can be deductively reasoned that you’ll experience traffic on your way home.

Another type of reasoning used in the workplace is inductive reasoning. This form of reasoning is the opposite of deductive reasoning and is when broad generalizations are made based on specific occurrences or facts. The following is an example of inductive reasoning: A lawyer analyzes various strategies used by other attorneys in cases that are similar to the lawyer’s current case. The lawyer uncovers a consistent strategy used by other lawyers that results in frequent acquittals and uses this approach in their case.

Inductive reasoning is equally vital in workplace settings and helps professionals use specific findings to come to a broader conclusion to solve problems.

There are several steps involved in the top-down thinking process to reach a viable conclusion. Most professionals rely on premises, or something that’s already assumed, to reach a deduction. Beyond identifying the premises in a particular situation, other steps you’ll likely take throughout this reasoning process include:

1. Ensure you fully understand the issue at hand and what’s at stake.
2. Analyze the data that relates to the issue at hand and ask questions when necessary to further your understanding.
3. Come up with a hypothesis, or a potential cause or reason for the issue at hand. This will be your initial assumption.
4. Test the validity of your hypothesis by applying a solution you believe will solve the issue.
5. Continue to test the hypothesis in other scenarios to further validate its effectiveness if the solution solves the issue in the desired way.
6. Based on the results of your testing, you can decide if the information uncovered related to the issue is invalid or valid.

Three types of deductive reasoning are seen most often in professional settings. These types of include:

1. Syllogism: This type of thinking is when you conclude from two assumed premises that both share a common term with the outcome. The following is an example of a syllogism: all cats are mammals, and all mammals have four legs. Therefore, all cats have four legs. While this statement isn’t necessarily true, it shows how two assumed premises can lead to a common conclusion.
2. Modus ponens: Modus ponens, also referred to as affirming the antecedent, is a type of reasoning in which the following formula is used: If P is true, and P implies Q, then Q will be true. For example, if Jane goes to work on Tuesdays, and today is Tuesday, then Jane is going to work today.
3. Modus tollens: Modus tollens is the opposite of modus ponens because it infers that if P implies Q, and Q is not true, then P is not true. For example, if Jane goes to work on Tuesdays, and Jane doesn’t go to work today, then today is not Tuesday.

The following are several examples of deductive logic to give you a better understanding of how this skill is used in real life:

• A marketing team performs market research related to how much time professional women who are also mothers have to spend on their makeup each day. Based on their findings, they discover that professional women who are also mothers rarely have more than 10 minutes each day to put on their makeup due to family responsibilities. Using this information, the marketing team advertises that their makeup product can be put on in under three minutes, leaving ample room for other activities involved in getting ready each day. They realize an increase in sales in this makeup product.
• A student at a local university was informed that the career center at their college is offering free help with resumes. Because the student is an active member of the college and they have a resume, they assume they will not need to pay to get help with their resume at the career center.
• A customer service center recently received an influx of customer complaints due to how long it takes a member of the customer service team to return customer calls. Therefore, if the customer service center begins providing faster return calls, the customer complaints will stop and customers will be more satisfied with their experiences.
• A clothing retail store owner notices a trend in which customers are buying more dark denim jeans than other varieties of denim jeans. The owner uses this information to spend most of their advertising dollars in a local magazine to promote the dark denim jeans available at their store and offers a discount on dark denim jean purchases.