Discounting our knowledge: Thinking of animal research as moral decision making

Trigger alert: This blog post contains pictures from animal experiments. You may find them disturbing, upsetting or misleading.

We can argue about human nature, and what ultimately makes us human, but one fact seems to meet public consensus. Humans are explorative. Curiosity towards our environment helps us to learn from our surroundings. Exploring the planet has led to a trade network that covers the world, allowing consumers to access exotic products, and supporting the supply of regions that are less suited for agriculture. Exploring the biological processes and developmental steps underlying diseases has led to a deepened understanding and allows us to develop drugs and treatment on an informed basis – contributing to health.

But just as the discovery of the new world that opened trade markets to the European customer harmed the indigenous people living in those areas, discovery of fundamental biological mechanisms harms these whose bodies are studied – research animals such as rodents.

There is a vast documentation of whether animal research is justifiable or not. This blog post tries to catch the reasons why the two parties of this discussion will never come to a consent.

Rodents are the most common mammalian model organisms – also in cognitive Neuroscience. Vdegroot (GFDL 1.2)

A formula for morality

The evaluation, if an experiment is morally justified or not, usually boils down to a utility function: We expect the experiment to result in a certain gain in knowledge (k). This gain comes at the cost of causing pain, suffering, or distress to the studied organism – I will refer to these three as harm (h). This is true for studies in humans and in animals. The amount of our gained knowledge is thus weighted by the amount of harm the experiment causes, resulting in the morality index (m). This index serves as an indicator, if the experiment is morally justified or not. The higher the amount of harm, the less we should accept the experiment. On the other hand, the more knowledge is generated by the experiment, the more harm can be justified.


The easiest formula to describe if an experiment is morally justified, simply compares the amount of knowledge (k) generated by the experiment to the amount of harm (h) that it causes and results in a morality index (m) that increases the more the experiment is considered to be “morally correct”.

Wait… a formula?

Putting the moral decision into a formula sounds brutal and heartless, though it is done for moral decision making more frequently than one might think. One example can be found here. Importantly, the formula above can be extended by a beautiful feature that captures the essence of the debate around animal research – the knowledge and the harm parameters can be modulated by a factor indicating the value one assigns to these factors. Thus, the gain in knowledge is weighted by a factor vk and the harm in our model organism is weighted by a factor vh. Normally, the value factors are constraint in their magnitude such that they can only discount or increase the amount of harm and knowledge to a certain extend. In the particular case of animal research, they seem unbound to such numerical frames. The value of vh, for example, can take values close to infinity – making the protection of the studied organism as important that no gain in knowledge could ever be morally justified if it comes along with pain, suffering, and distress.

The extension of the formula to compute the morality index for an experiment with value parameters vk and vh can change the outcome completely. The morality index now depends on the value parameters as much as on the actual amounts of knowledge and harm.

There are different ways to change the morality index of an experiment. As in the example above, one could tune the value parameters to drastically modify the perception of the experiment without really changing the parameters referring to the actual amount of knowledge and harm. Since value parameters are hard to quantify, research institutes conducting animal experiments and websites such as “understanding animal research”, or the german equivalent “Tierversuche verstehen”, prefer to point out how they increase the amount of knowledge (k) and reduce the amount of harm (h) without focussing on their value.

Gains in knowledge

In some cases, it is obvious what we learn from an experiment – is a particular drug toxic in a mammalian organism? In other cases, the applicability of knowledge is less obvious – how does visual attention emerge in the cortex? To understand the relevance of these questions, it helps to think of scientists as data-hamsters. They collect all kinds of information that seems useful and store it somewhere – for later purposes. The pool that has aggregated in this way is getting larger and larger, and provides a wealth of information to any motivated developer. Researchers point out that laymen do not have enough insight into the field, and therefore underestimate the value of pieces of information brought to that pool – resulting in a wrong estimate of the amount of knowledge (k). Animal rights activists rather blame researchers for getting the value of knowledge (vk) essentially wrong, ignoring the relevance of their study for the sake of reputation. But disregarding how relevant or irrelevant the research question might be, morally, one could study anything – given no harm was involved. This can be seen in the model proposed above: when the combined amount of harm and the value (vh) connected to it get very low (dropping below one), the morality index increases.

Greife nach dem Licht / Reach for the light
Berger Quelle: Deutsches Primatenzentrum

How much does it hurt?

The most striking difference in how animal research is presented to the public is not found in the discussion of its relevance (i.e. the amount of knowledge) but in the amount of harm caused by animal experiments. The most recent efforts of research institutes and the government to constrain this amount of harm in animal research are the 3-R-principles: replace, reduce, and refine. These three words serve as a guideline for researchers to limit the number of procedures involving animals by replacing them with alternative procedures, to reduce the number of animals in each experiment by assuring a high standard of data quality, and to refine the procedures such that animals suffer as little as possible. This involves housing and feeding standards as well as extensive training, for example, to get macaques used to the primate chair in which they sit during experiments.

The effort that is undertaken to keep animal research restricted and controlled is high – certainly also due to the low public acceptance. However, the fact remains that an animal experiment is defined as a procedure that potentially causes pain, suffering or distress. And given that the motivation to avoid harm can be infinitively high, any amount of harm will make any experiment morally unjustifiable.

Rhesusaffe im Primatenstuhl bekommt eine Belohnung.
Depending where you search for information, animal research might look quite different.      Left: Mast Quelle: Deutsches Primatenzentrum. Right: Peta USA.

Infinity over infinity

Of course, the moral decision model I’ve been introducing can be extended into many other dimensions. One of the most important factors that is often used to justify animal research is that it prevents human harm. If I put that into the moral decision formula, I would have to include a term in the numerator that captures prevented harm (in humans) and weights this by how much we would value it. With that term, we would run into a major moral dilemma. Now, we directly compare human harm to harm put on research animals. It is tempting to cancel them out by division. But, if both, the value of preventing human harm and avoiding harm in research animals are infinitively high, the dilemma is as well a moral as a mathematical one – infinity over infinity has no logical value, it is meaningless.

In the End – where do we start?

In the discussion “Animal research – morally justified or not?”, we are permanently confronted with a mesh-up of two dimensions: the actual amount of knowledge we gain from an experiment and the amount of caused harm are confounded with the value factors that can scale up or diminish this first dimension until its actual size becomes unrecognizable. The first and most important task to solve this dilemma is getting clear about the values of knowledge and harm. Recently, the Max-Planck-Gesellschaft took the very first step in that direction, publishing a White Paper in which the society justifies animal experiments in basic research. In this paper, the MPG argues for a viewpoint that “grades moral considerations as a function of the differentiation and complexity of mental capabilities, both in animals and humans. Thus, animals with more differentiated mental abilities are accorded a higher moral status than animals with less developed mental abilities.”. Here, it becomes clear that the moral value of prevented human harm is estimated higher than the moral value of harm caused in research animals. In the same line, the White Paper states that “the gain of knowledge is assigned a value as a precondition for potential future contributions to problem solving”, thereby assigning a value parameter to knowledge as in the model I proposed above.

As hard as this argumentation might be to swallow, it is one of the most honest stands I’ve came across while researching for this post, and it pinpoints the controversy in animal experimentation. If we want to justify animal research, we need to discount their harm by our knowledge.

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