14.3 Negligence: Causation, Damages, NIED & Comparative Fault
Key Takeaways
- Actual causation (cause-in-fact) requires the 'But-For' test for single causes, the 'Substantial Factor' test for concurrent merged causes (Kingston), or 'Alternative Liability' to shift the burden of proof when multiple defendants acted negligently but only one caused harm (Summers v. Tice).
- Proximate causation requires that the plaintiff's injury was a foreseeable result within the scope of risk created by defendant's conduct; dependent intervening forces (ordinary medical malpractice, rescuers under 'danger invites rescue') do not break causation, whereas extraordinary unforeseeable forces (unforeseeable crimes, acts of God) act as superseding causes.
- Negligence requires actual physical injury or property damage; nominal damages are barred, and the Economic Loss Rule prohibits recovery for purely financial losses without physical impact; under the Eggshell Skull Plaintiff rule, defendant is fully liable for all physical consequences regardless of latent frailty.
- Negligent Infliction of Emotional Distress (NIED) is restricted to: (1) Zone of Danger (near-miss physical threat + physical symptoms); (2) Bystander Claims (close relative present at scene contemporaneously observing catastrophic injury under Dillon/Thing); or (3) Special Pre-existing Relationships (e.g., mishandling corpse).
- Defenses to negligence include Contributory Negligence (complete common law bar, mitigated by Last Clear Chance), Pure Comparative Negligence (plaintiff recovers damages reduced by fault percentage, even if 90% at fault), and Modified Comparative Negligence (plaintiff barred if fault exceeds 50% under the 51% rule or equals 50% under the 50% rule).
14.3 Negligence: Causation, Damages, NIED & Comparative Fault
Once duty and breach are established, the plaintiff must prove that the defendant's breach caused the plaintiff's injuries and that the plaintiff suffered legally cognizable damages. Furthermore, the defendant may raise affirmative defenses based on the plaintiff's own comparative fault or assumption of risk.
1. Actual Causation (Cause-in-Fact)
Actual cause establishes the factual connection between the defendant's breach and the plaintiff's harm. Courts apply three distinct tests depending on the factual scenario:
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| ACTUAL CAUSATION DECISION TREE |
| |
| SINGLE DEFENDANT / CAUSE? |
| --> Apply BUT-FOR TEST: "Injury would not have occurred BUT FOR breach." |
| |
| MULTIPLE INDEPENDENT MERGED CAUSES (Each sufficient alone)? |
| --> Apply SUBSTANTIAL FACTOR TEST (Kingston merged fires doctrine). |
| |
| MULTIPLE NEGLIGENT DEFENDANTS, ONLY ONE CAUSED HARM (Uncertain which)? |
| --> Apply ALTERNATIVE LIABILITY (Summers v. Tice): Shifts burden of |
| proof to defendants; joint and several liability if neither exonerates|
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1. The "But-For" Test
- Standard: The injury would not have occurred but for the defendant's negligent conduct.
- Application: Used in the vast majority of single-cause tort actions.
2. The Substantial Factor Test (Concurrent Merged Causes)
- Standard: Where two or more independent negligent acts combine concurrently to produce a single indivisible injury, and each act alone would have been sufficient to cause the entire harm, each defendant's act is deemed an actual cause if it was a substantial factor in bringing about the injury (Kingston v. Chicago & N.W. Ry.).
3. Alternative Liability Theory (Summers v. Tice)
- Standard: Where two or more defendants act negligently toward the plaintiff at the same time, but only one defendant caused the plaintiff's harm, and it is impossible for the plaintiff to determine which one, the court shifts the burden of proof to each defendant to prove they did not cause the injury.
- Result: If a defendant cannot exonerate themselves, all defendants are held jointly and severally liable.
2. Proximate Cause (Scope of Liability) & Intervening Forces
Proximate cause is a policy determination limiting a defendant's liability to harms that bear a foreseeable relationship to the defendant's negligent conduct (The Wagon Mound No. 1).
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| PROXIMATE CAUSE & INTERVENING FORCES MATRIX |
| |
| DEFENDANT'S BREACH -----> INTERVENING FORCE -----> PLAINTIFF'S INJURY |
| |
| DEPENDENT / FORESEEABLE INTERVENING FORCES (Defendant REMAINS LIABLE): |
| [+] Subsequent Ordinary Medical Negligence (malpractice is foreseeable) |
| [+] Negligence of Rescuers ("Danger invites rescue" - Wagner) |
| [+] Reactions to Peril / Escape Efforts |
| [+] Subsequent Diseases or Secondary Accidents Weakened by First Injury |
| |
| SUPERSEDING / UNFORESEEABLE FORCES (Defendant DISCHARGED from Liability): |
| [-] Intentional Crimes / Torts of 3rd Parties (unless foreseeable) |
| [-] Extraordinary, Gross Medical Malpractice |
| [-] Unforeseeable Acts of God / Extraordinary Natural Disasters |
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Intervening vs. Superseding Forces
- Intervening Force: An active force that comes into operation after the defendant's negligent act and contributes to producing the plaintiff's injury.
- Dependent (Foreseeable) Intervening Forces: Forces that are normal, natural responses to the situation created by defendant's negligence. Defendant remains liable.
- Medical Malpractice: Ordinary medical negligence that aggravates an initial injury is deemed a foreseeable dependent risk.
- Rescuer Rule (Wagner v. International Ry.): "Danger invites rescue." An original tortfeasor is liable for injuries suffered by a rescuer who acts reasonably to assist a victim.
- Superseding Forces: An unforeseeable, extraordinary intervening force that breaks the causal chain and completely relieves the original defendant of liability for injuries occurring thereafter.
- Criminal Acts: A third party's criminal act or intentional tort is typically a superseding cause, UNLESS the defendant's initial negligence created or increased the foreseeable risk of that specific criminal conduct (e.g., a landlord who leaves a security gate broken in a high-crime area is liable when a tenant is assaulted by an intruder).
3. Legally Cognizable Damages & Rules of Calculation
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| NEGLIGENCE DAMAGES RULES |
| |
| 1. ACTUAL HARM REQUIRED: Physical injury or property damage mandatory. |
| (Nominal damages NOT permitted; Economic Loss Rule bars pure money) |
| |
| 2. EGGSHELL SKULL RULE: Defendant takes plaintiff as found. Full extent |
| of physical injury is compensable, even if unforeseeably severe. |
| |
| 3. COLLATERAL SOURCE RULE: Payments from insurance or third parties do |
| NOT reduce defendant's damages liability. |
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Core Damages Principles
- Actual Harm Mandatory: A plaintiff cannot maintain a negligence action without actual, demonstrable physical injury or property damage. Nominal damages are not available in negligence.
- The Economic Loss Rule: A plaintiff cannot recover in negligence for purely economic losses (e.g., lost profits) unaccompanied by physical damage to the plaintiff's person or property.
- The Eggshell Skull Plaintiff Rule (Vosburg v. Putney / Benn v. Thomas): Once the plaintiff establishes the prima facie elements of negligence, the defendant is liable for the full extent of all physical injuries suffered by the plaintiff, even if the severity of the injury was completely unforeseeable due to the plaintiff's pre-existing frailty or latent medical condition.
- The Collateral Source Rule: Compensation received by the plaintiff from independent collateral sources (e.g., private health insurance, disability benefits, or sick leave) is not deducted from the damages the defendant is required to pay.
4. Negligent Infliction of Emotional Distress (NIED)
Under common law, courts strictly limit claims for purely emotional harm unaccompanied by direct physical impact to three recognized categories:
| NIED Category | Primary Legal Standard | Mandatory Prerequisites | Key Precedent |
|---|---|---|---|
| Near-Miss / Zone of Danger | Plaintiff within the physical area of danger created by defendant's negligence | 1. Plaintiff in immediate zone of physical danger;<br>2. Severe emotional distress;<br>3. Physical manifestations (e.g., heart attack, shock). | Consolidated Rail Corp. v. Gottshall |
| Bystander Recovery | Plaintiff witnesses catastrophic injury to a close relative | 1. Closely related to victim (parent, child, spouse);<br>2. Present at the accident scene;<br>3. Contemporaneous sensory perception of the impact. | Dillon v. Legg / Thing v. La Chusa |
| Special Relationships / Pre-existing Duty | High foreseeable risk of severe emotional trauma from breach of specific duty | Pre-existing fiduciary or contractual relationship where distress is highly foreseeable (e.g., mishandling a corpse, false death telegram). | Common Law Direct Victim Doctrine |
5. Defenses to Negligence & Comparative Fault Systems
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| COMPARATIVE FAULT SYSTEMS MATRIX |
| |
| SYSTEM RULE ON RECOVERY SAMPLE CALCULATION |
| --------------------- --------------------------- -------------------- |
| Contributory ANY plaintiff negligence P 1% at fault = |
| Negligence (Common L.) COMPLETELY BARS recovery. $0 Recovery. |
| |
| Pure Comparative P recovers damages reduced P 90% at fault, $100k |
| Negligence by % fault, NO BAR. damages = $10,000 Rec.|
| |
| Modified Comparative P recovers ONLY if fault is P 50% fault = $0 Rec. |
| (50% Bar Rule) STRICTLY LESS than D (<= 49%) |
| |
| Modified Comparative P recovers IF fault is NOT P 50% fault = 50% Rec.|
| (51% Bar Rule) GREATER than D (<= 50%) P 51% fault = $0 Rec. |
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1. Traditional Contributory Negligence
- Rule: At common law, any contributory negligence by the plaintiff—no matter how minor—constitutes an absolute and complete bar to recovery.
- The Last Clear Chance Doctrine (Contributory Negligence Exception): If the defendant had the "last clear chance" to avoid the accident through the exercise of reasonable care and failed to do so, the plaintiff's contributory negligence is excused, and the plaintiff may recover full damages.
2. Comparative Negligence (Modern Law)
- Pure Comparative Negligence (Default MBE Rule unless specified): The plaintiff's recoverable damages are reduced strictly by the plaintiff's percentage of fault. A plaintiff who is 90% at fault can still recover 10% of their damages.
- Modified Comparative Negligence (Partial Comparative Fault):
- 50% Bar Rule ("Not as Great as" / Equal Fault Bars): Plaintiff is barred from recovery if the plaintiff's fault is equal to or greater than 50% (plaintiff recovers only if fault is 49% or less).
- 51% Bar Rule ("Not Greater Than" / Greater Fault Bars - Majority Modified Rule): Plaintiff is barred from recovery if the plaintiff's fault is strictly greater than 50% (plaintiff recovers reduced damages if fault is 50% or less).
3. Assumption of the Risk
- Express Assumption of Risk: An express contractual exculpatory agreement bars recovery unless it violates public policy (e.g., gross negligence or essential public services).
- Implied Assumption of Risk: The plaintiff (1) had actual subjective knowledge of the specific risk; and (2) voluntarily encountered the danger. In modern comparative fault jurisdictions, implied assumption of risk is merged into the general comparative fault calculation.
Two independent hunters, standing twenty yards apart in a wooded field, simultaneously and negligently fire their shotguns in the direction of a nearby walking trail. Both hunters were using identical gauge shotguns loaded with identical birdshot pellets. A hiker on the trail is struck in the eye by a single birdshot pellet and loses vision in that eye. Ballistics experts confirm that only one pellet struck the hiker, but it is impossible to determine from which hunter's shotgun the pellet was fired. The hiker sues both hunters for negligence. How should the court resolve the actual causation element?
A motorist negligently runs a red light and broadsides a passenger car, breaking the passenger's leg. The passenger is transported to a local hospital where an orthopedic surgeon performs surgery to set the fractured bone. During the surgery, the surgeon commits ordinary medical malpractice by improperly applying an internal fixation plate, resulting in a severe bone infection that requires a second surgery and extended rehabilitation. In a negligence action by the passenger against the motorist, the motorist moves to dismiss the claim for damages resulting from the infection, arguing that the surgeon's medical malpractice was an intervening superseding cause. How should the court rule on the motorist's motion?
A mother and her eight-year-old son were walking hand-in-hand on a public sidewalk. A negligent driver lost control of his vehicle, jumped the curb, and violently struck the child. The mother was not touched by the car, but she witnessed the impact and the catastrophic injuries to her son from two feet away. As an immediate consequence of witnessing the collision, the mother suffered severe emotional trauma and acute cardiovascular shock requiring hospitalization. If the mother sues the driver for Negligent Infliction of Emotional Distress (NIED), will she prevail?
In a jurisdiction that has adopted the modified comparative negligence rule with a 51% bar (the 'not greater than' rule), a plaintiff brings a negligence action against a defendant arising out of an automobile collision. The jury determines that the plaintiff suffered $100,000 in total damages and assigns 40% of the fault to the plaintiff and 60% of the fault to the defendant. What amount, if any, is the plaintiff entitled to recover from the defendant?