Determining Actual Causation In Personal Injury Cases: 3 Tests To Use

9 July 2015
 Categories: , Articles


Personal injury cases can take a long time to settle – mostly because it can be difficult to determine actual causation. If you're unsure which party should be held liable for the negligent action that caused your accident, speak with an experienced personal injury attorney as soon as you can with the evidence you have compiled. Most attorneys will use several tests to come to an informed conclusion. This article will look at 3 of the most common tests used.

The "But For" Test

The "but for" test is perhaps the simplest test used by personal injury attorneys to determine causation. The test simply fills in the blank of the following question: "but for the existence of X, would Y have occurred?" X is considered as the actual causation and Y is the accident or the injury caused.

Although the "but for" test is generally quite useful, it can be ineffective if there are concurrent causes, sufficient combined causes and market share evidence. A concurrent cause is defined as when two separate negligent acts resulted in the injury or harm and both negligent acts are liable. A sufficient combined cause is defined when two separate negligent acts could have resulted in the injury and either of which would have been sufficient. Market share evidence is defined as injuries caused by products made by different manufacturers. In this situation, it is difficult to determine which manufacturer is liable.

If there are any discrepancies after the "but for" test, your personal injury attorney may need to apply an addition test to determine which negligent party is most liable for your injuries.

The Direct Causation Test

The direct causation test is much simpler, and only addresses the metaphysical concept of causation. In short, it does not take into account whether the negligent party would have been able to foresee the possibility of harm as long as his or her actions were responsible for the accident. The direct causation test also does not take into account the culpability of the negligent party. In fact, it only looks at whether there was an intervening cause between the negligent act and the harm.

An intervening cause can be better defined as three separate conditions. The intervening cause needs to be independent of the original act being tested in the direct causation test, be a voluntary action and occur between the timeframe of the original act by the negligent party and the accident. For an action to be deemed as the cause, there must not be an intervening cause.

The Harm within the Risk Test

The strictest of the causation tests is probably the 'harm within the risk test', which was made famous in the Palsgraf v. Long Island Railroad Co. case of the New York State Law. This test determines whether the victim of the injuries, or you, could have foreseen the dangers. Most personal injury attorneys agree that this test is the hardest to apply due to the controversies surrounding it. In particular, some attorneys and judges believe that the 'harm within the risk test' is more concerned with culpability than actual causation.

The 'harm within the risk test' focuses more on whether the injured party was a member of the class of people most likely to be put at risk for the accident caused. As a result, it only looks at one single factor of actual causation, and cannot be the sole test used for determining the actual cause of the accident.


Upon determining actual causation, your personal injury attorney will have a better idea regarding which negligent party is most liable and can begin building a legal suit for seeking compensation. If the attorneys can identify without a doubt which party is negligent and the specific action that caused the injury or accident, you'll have a much easier time negotiating a settlement. Read more or contact a professional for information about your specific case.