Cause and effect and course of action

In short

These are two closely linked verbal-reasoning formats. In cause and effect, two events are given and you must decide which one produced the other, whether both flow from a third hidden cause, or whether they are unconnected. In course of action, a problem situation is given with two or three suggested steps, and you must decide which steps are relevant, practicable and proportionate enough to "follow". Both are examined in IBPS/SBI and RRB reasoning, insurance and state PSC papers, SSC, MAT/CMAT, UPSC CSAT Paper II (decision making, which carries no negative marking) and in campus aptitude tests such as TCS NQT, Capgemini, Cognizant, Wipro and Accenture. The same thinking is used at work in root cause analysis, incident management, insurance claim settlement and administrative note-writing. Paper patterns shift from year to year, so confirm the current syllabus in the latest notification.

Explained

What a cause and an effect actually are

• Cause: an event or condition whose occurrence brings about another event. Effect: the event brought about.
• Necessary condition: without it the effect cannot happen (oxygen for fire). Sufficient condition: its presence alone guarantees the effect. Many exam "causes" are only contributory - one of several conditions.
• Proximate (immediate) cause: the nearest event in the chain, the one that directly triggers the effect. Remote (ultimate) cause: the original condition several links back.
• Principal cause: the most important contributor when several act together; exam keys usually want the proximate or principal cause, not a remote one.
• Common cause: a single hidden event that produces both given statements independently (heavy rain causing both waterlogging and a school holiday).
• Independent causes: two separate events, neither causing the other, that both push towards some third unstated effect.
• A chain is cause → intermediate effect → final effect; an effect can itself be the cause of the next event.

The five standard options and the test for each

In the usual format, Statement I and Statement II are both facts. Choose one of:

1. I is the cause and II is its effect.
2. II is the cause and I is its effect.
3. Both I and II are independent causes.
4. Both I and II are effects of independent causes.
5. Both I and II are effects of a common cause.

• Some sets add "both are effects of a common cause or the cause is not inferable"; read the instruction line, because the option wording decides the answer.

Working tests for causal questions

1. Chronology test: a cause cannot come after its effect. Words like "last week", "since April", "has now been announced" fix the order.
2. Direction test: write both arrows (I → II and II → I) and ask which one survives. If a policy and an outcome are paired, the policy is normally the cause - unless the outcome is a *reason given for* the policy, when it reverses.
3. Plausibility and immediacy test: reject a link that needs three extra assumptions. Prefer the closest cause available in the two statements.
4. Scope and magnitude test: a local, small event cannot cause a national or very large effect, and vice versa - one factory closing does not raise the country's unemployment rate.
5. Common-cause test: if each statement individually sounds like a *result* (prices rose, trains cancelled, exams postponed), look for one external trigger behind both.
6. Correlation is not causation: two things moving together may share a cause (confounding) or coincide. Asserting causation from mere sequence is the post hoc ergo propter hoc fallacy; from mere co-occurrence, cum hoc ergo propter hoc.
7. No outside information: use general awareness only to judge plausibility, never to supply a fact that contradicts the statements. The statements are to be accepted as true.

Mill's methods - the logic behind causal inference

Examined in logic and research-methodology papers under inductive reasoning:

• Method of agreement: if several cases of an effect share only one circumstance, that circumstance is the probable cause.
• Method of difference: two cases alike in all respects except one, where the effect occurs in only one case - the differing circumstance is the cause.
• Joint method of agreement and difference: apply both - the standard logic of a control group.
• Method of residues: subtract the parts of a phenomenon already explained; the residue belongs to the remaining antecedent.
• Method of concomitant variations: when A varies, B varies in a regular way - A and B are causally connected or share a cause.
• Limitations: these methods can miss plural causes, multiple effects of one cause, and confounders; they establish probable, not certain, causation.

What counts as a course of action

• A course of action is a practical, administrative or follow-up step suggested to solve, contain or prevent the problem stated.
• The statement is a problem, finding, report or policy fact; the suggested actions typically begin with "should".
• Options are usually: only I follows / only II follows / either I or II follows / neither follows / both follow (with three actions, combinations such as "I and III follow").
• "Follows" means the action is a fit, workable and reasonable response - not that it is the only possible or the best conceivable response.
• Distinguish immediate (relief) action from long-term (preventive) action. A good set often contains one of each and both follow.

Filters for accepting or rejecting an action

1. Relevance: does it address the problem in the statement, or some other issue?
2. Root-cause test: does it attack the cause, or only the symptom? Symptom relief is still acceptable as an immediate step.
3. Feasibility: is it possible with realistic money, manpower, time and technology? "Build a hospital in every village by next month" fails.
4. Authority test: can the named actor legally do it? A school cannot change a state law; a municipal body cannot alter the repo rate.
5. Proportionality: drastic actions - ban, close permanently, dismiss all staff, cancel the examination - almost never follow, unless the statement itself describes an extreme danger.
6. No new harm: an action that shifts the problem elsewhere, punishes the victims, or is unethical or illegal does not follow.
7. Not a mere fact, opinion or wish: "People should be more careful", "This shows poor planning", "The government must think about it" are not courses of action.
8. Already in force: if it is standard practice already being followed, it adds nothing - except where the option says "should be continued/strengthened", which can follow.
9. "Either/or" rule: both actions follow *and* either one alone is enough to settle the matter, usually two alternative ways of doing the same thing.
10. Vagueness test: "Suitable steps should be taken" is too vague to be a course of action.

Signal words that decide most questions

Key points

• Cause - what produces; effect - what is produced; both statements in the question are given as facts.
• Chronology rule - an effect never precedes its cause; dates and tenses settle most items.
• Proximate cause - the nearest trigger; exam keys prefer it over a remote background cause.
• Principal cause - the dominant one among several contributors.
• Common cause - one hidden event explains both statements; suspect it when both read like outcomes.
• Independent causes - neither causes the other, both drive the same unstated result.
• Effects of independent causes - the two facts are substantively unrelated.
• Correlation vs causation - co-movement may arise from a confounder, reverse causation or coincidence.
• Post hoc fallacy - treating "after this" as "because of this".
• Mill's canons - agreement, difference, joint method, residues, concomitant variations.
• Course of action - a practical follow-up step, not an opinion, fact or appeal.
• Relevance, feasibility, authority, proportionality - the four main filters for an action.
• Immediate plus long-term - the commonest correct pair in three-action sets.
• Extreme words - ban, all, permanently, dismiss - almost always make an action fail.
• Either/or - two interchangeable remedies, each sufficient on its own.
• Neither follows - both actions are impractical, irrelevant or harmful.
• No external facts - accept the statement as true; use awareness only to judge plausibility.
• Vague actions - "suitable steps should be taken" never follows.

Examples

Example 1 - common cause. I: Many schools in the district declared an unscheduled holiday on Tuesday. II: Several low-lying roads in the district remained waterlogged on Tuesday. *Step 1 - chronology:* both are the same day, so neither clearly precedes the other. *Step 2 - direction:* waterlogged roads do not force a holiday by themselves (schools can still run), and a holiday certainly does not flood roads. *Step 3 - common cause:* very heavy rainfall on Monday night explains both independently. Answer: both I and II are effects of a common cause.

Example 2 - reverse direction trap. I: The Reserve Bank of India raised the policy repo rate at its last review. II: Retail inflation stayed above the upper limit of the RBI's tolerance band for three consecutive months. *Step 1:* the natural reading is "policy first, outcome later", which tempts option 1. *Step 2 - chronology:* II describes three months already elapsed, so it is prior. *Step 3 - plausibility:* under flexible inflation targeting (Section 45ZA, RBI Act, 1934), the target has been 4% with a ±2% band, reviewed every five years, and a sustained breach is precisely the trigger for a rate increase. Answer: II is the cause and I is its effect.

Example 3 - independent causes. I: There was a cloudburst over the city between 2 a.m. and 5 a.m. II: A major water supply pipeline burst near the city's main junction the same night. *Step 1 - direction:* rain does not burst a pipeline in this statement, and a pipeline burst does not cause rain. *Step 2:* they are not effects of one event either - rain is natural, the burst is an asset failure. *Step 3:* both independently cause the same outcome - flooding and traffic breakdown. Answer: both I and II are independent causes.

Example 4 - course of action with immediate and long-term steps. Statement: Over thirty students of a government hostel fell ill after dinner in the mess. I. The mess should be closed down permanently. II. The affected students should be shifted to hospital at once and food samples sent for laboratory testing. III. The kitchen should be inspected and the mess staff retrained in food hygiene before it reopens. *I:* extreme and it punishes all residents; a defect in one meal does not justify permanent closure - does not follow. *II:* immediate relief plus identification of the cause, fully within the warden's authority - follows. *III:* long-term preventive step, feasible and relevant - follows. Answer: II and III follow.

Example 5 - "either or" and "neither". Statement: The office canteen, built for 150 people, cannot cope with the rush when all 300 employees break for lunch at 1 p.m. I. Lunch break should be staggered into two batches of 150. II. The canteen's seating should be expanded to 300. Each alone removes the crowding; the question is answered by either - either I or II follows. Now replace them with: I. Employees should be told to skip lunch on busy days. II. The canteen should be shut down. Both create a larger problem and address nothing - neither follows.

Where it is used

• Quality and manufacturing: root cause analysis with the 5 Whys and the Ishikawa (fishbone) diagram classified by the 6 Ms - man, machine, material, method, measurement, environment - and CAPA documentation under ISO 9001 and Schedule M for pharma plants.
• IT services and operations: incident versus problem management in ITIL at TCS, Infosys, Wipro and Cognizant - an immediate workaround (course of action) plus an RCA report naming the proximate cause, with an RCA document due to the client within a fixed window.
• Insurance and banking: the doctrine of proximate cause decides claim admissibility, codified for marine insurance in Section 55 of the Marine Insurance Act, 1963, and applied by insurers under IRDAI rules; chain-of-causation reasoning in fraud and credit loss investigation.
• Safety and accident inquiry: notifiable accidents (notice under Section 88 of the Factories Act, 1948) and their investigation, DGFASLI guidance, and inquiries by the Commissioner of Railway Safety - findings separate immediate cause, underlying cause and corrective action.
• Public administration and policy: district-level problem notes, UPSC CSAT decision-making questions, and the structure of a government note - problem, cause, options, recommended course of action.
• Job roles: quality engineer, Six Sigma Green Belt, service-desk and SRE engineer, claims assessor, management trainee, bank PO and civil services aspirants.

Interview questions

• Q: What is the difference between a cause and an effect? A: The cause is the event that brings about the change; the effect is the resulting event. The cause must be prior in time and must be capable of producing the effect on its own or with normal background conditions.
• Q: How do you recognise that two statements are effects of a common cause? A: When neither can plausibly produce the other but a single external event - rain, a strike, a budget decision - explains both independently.
• Q: What is the difference between proximate and remote cause? A: The proximate cause is the nearest trigger in the chain; the remote cause is an earlier condition. Insurance claims and accident inquiries turn on the proximate cause.
• Q: Why is correlation not causation? A: Two variables can move together because of a third confounding factor, because the direction is reversed, or by coincidence; co-movement alone proves no mechanism.
• Q: What is the post hoc fallacy? A: Concluding that because B followed A, A caused B - sequence in time is necessary for causation but not sufficient.
• Q: Name any two of Mill's methods of causal inquiry. A: The method of difference - two otherwise identical cases differing in one circumstance where the effect appears only once; and the method of concomitant variation - the effect varies regularly with the suspected cause.
• Q: What makes a suggested step a valid course of action? A: It must be relevant to the stated problem, practicable with available resources, within the authority of the actor, and proportionate - not drastic or harmful.
• Q: Why do actions containing "all", "permanently" or "ban" usually fail? A: They are disproportionate to the problem described and normally create larger problems than they solve; exams treat them as extreme.
• Q: When do you answer "either I or II follows"? A: When both actions are acceptable and either one alone fully addresses the problem - two interchangeable remedies rather than complementary ones.
• Q: Should an immediate relief measure be accepted even if it does not remove the cause? A: Yes. Relief and prevention are separate; the standard answer in three-action sets is one immediate measure plus one long-term measure.
• Q: You run an RCA for a production outage. What do you report? A: The immediate trigger, the underlying cause, the sequence of events with timestamps, the containment action already taken, and a time-bound corrective and preventive action with an owner.
• Q: A manager says attrition rose because a competitor opened an office nearby. How would you test that claim? A: Check chronology, compare exit-interview reasons against pay and roster data, and look at teams without competing offers nearby - a control comparison in the spirit of Mill's method of difference.

Common mistakes

• Assuming the first statement is always the cause because it is printed first; always test both directions.
• Treating mere sequence or co-occurrence as causation, and missing the common-cause option.
• Choosing a remote background cause when a proximate cause is available in the statements.
• Importing outside facts to contradict the given statements, instead of accepting them as true and using awareness only to judge plausibility.
• Accepting a drastic or punitive course of action because it is forceful - closing a facility, dismissing staff, cancelling an exam.
• Rejecting an immediate relief step on the ground that it does not remove the root cause; both can follow.
• Ignoring the authority test, and accepting actions the stated body has no power to take.
• Marking "both follow" by default in two-action sets without checking whether either alone would suffice, which makes it an "either/or".

Related topics

Statements and assumptions · Statements and conclusions · Critical reasoning: arguments and inferences · Data sufficiency · Syllogisms · Decision making and problem solving