1.Background

Generally, in tort or breach of contract cases, unique aggravating circumstances of the victim or aggrieved party is not taken into account in determining causation.  This is commonly known as the “thin-skulled plaintiff rule.” (Also known as “eggshell skull rule”).Relatedly, Article 127, paragraph 1 of the Civil Code provides that “if the injured party’s own negligence, in part, caused or contributed to the injury, the court may reduce or eliminate the damages.”  (Commonly known as “comparative negligence”).  But, if the above-referenced contribution or causation is merely the injured party’s unique circumstances, such circumstances are not regarded as“negligence.”  As such, comparative negligence would not apply.  However, it remains controversial whether comparative negligence can be "analogically applied" to reduce damages in cases where the injured party partly caused or aggravated its own injury.

2. In Japan

In Japan, whether in practice or theory, the victim's personality, pre-existing diseases, or physical characteristics which jointly cause the occurrence or aggravation of injury are collectively considered "factors."

In practice, Japanese comparative negligence jurisprudence essentially acknowledges that, where the injured party has “factors” that jointly cause or aggravate the injury -and it is unfair to hold the tortfeasor entirely liable- the court should reduce the damages accordingly.  This “reduction by factors” doctrine is part of various Japanese judgments.

But in practical terms, applying the “reduction by factors” doctrine requires further division of the “factors.”  Where the injured party has “mental factors” or “pre-existing medical conditions,” the Supreme Court of Japan has affirmed the application of “reduction by factors.”  But if the victim’s factors are merely “physical characteristics,” the Supreme Court of Japan held that “reduction by factors” shall not apply unless such characteristics rise to the level of “disease.”  Also, in respect to employer’s liability in cases where overworking caused an employee’s death, factors such as “personality” or “personal weakness” cannot be used to reduce damages unless such factors exceed the expectation and thus are not reasonably foreseeable.

3. In Taiwan

In Taiwan, most courts affirm the application of comparative negligence in cases of unique circumstances.  For example, Taiwan High Court’s judgment 96-Chong-Shang-Zi No. 351 states:“If the occurrence or aggravation of physical injury is comparative with the victim’s special personal, physical conditions or diseases, and the occurrence or scope of injury obviously exceed the common expectation given the circumstances of the tort, and the injury is affected by the victim’s unique physical or mental circumstances, further it would be unfair to hold the tortfeasor entirely liable, Article 217, paragraph 1 of the Civil Code may be analogically applied to take into consideration of such factors in determining total damages.‘Party A's depression and diminished capacity to be self-sufficient obviously exceeds the expectation given the circumstances of common traffic accidents and their reasonably associated scope of damages; along with party A’s advanced age, poor response to treatment, and post-injury irregular treatment regimen, combined to aggravate the injury.  It would violate fairness to hold Party B entirely liable for all damages.  Given the above, Article 127, paragraph 1 of the Civil Code shall be analogically applied to consider these factors and reduce the damage amount with respect to such aggravation.” (Based on the author’s research, this case seems to be the earliest judgment in Taiwan that expressly affirmed the analogical application of comparative negligence).

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