This is a draft - it will be updated later.
Probably 😬
This is a brief thread / blog post about how concepts from behavior change science would map onto medical concepts.
If you’re seeing this in the fediverse, the URL to the blog post is https://sciencer.eu/posts/2025-10-behavior-change-using-medical-analogies.html.
The vocabulary we use here is based on the Intervention Mapping protocol. If you want to check these more in depth, you can have a look at the Acyclic Behavior Change Diagram article at https://doi.org/jp9t, or the glossary for the Intervention Mapping Work Book at https://im-wb.com/glossary.html.
Where in behavior change science we focus on addressing issues in society or at a larger scale where human behavior plays a role, medicine is concerned with issues in the human body. The analogy for the behavior we ultimately want to change is therefore a disease.
When a disease is cured or changed a behavior is changed, medicine and behavior change science’s job is done; so in a way we started at the end of the story.
The story begins with the diagnosis. In medicine, this process establishes what exactly the situation is and how the disease at hand can be targeted. In behavior change science, this consists of two things:
1️⃣ the needs assessment, to establish the broader context; 2️⃣ and determinant studies to establish what exactly should be targeted.
Especially determinant studies can be considered similar to the differential diagnosis: is the cause habits, perceived norms, or attitudes?
Once the diagnosis has been made, to address a disease, medicine uses, well, medicine. The analogy of a medicine is a behavior change intervention.
This medicine works through a mechanism of action. This is the theoretical process through which it targets whatever it targets.
Such mechanisms of action are clever exploitations of nature.
They leverage dynamics that generally evolved for wholly different purposes. For example, some medication binds to certain receptors or mimics a hormone.
This analogy also holds for the mechanisms of action in behavior change interventions. These mechanisms of action are the behavior change principles (behavior change methods in Intervention Mapping terms).
In medicine, the mechanisms of action are based on an understanding of the human body: anatomy, physiology, neurology, etc. Because we have theories about how the human body works, we can design medication that works with the natural processes that make our bodies work.
In behavior change science, the mechanisms of action are based on an understanding of the human psyche: health psychology, social psychology, cognitive psychology, etc. Because we have theories about how the human psyche works, we can design interventions that work with the natural processes that make our mind work.
Like in medicine, the mechanisms of action of behavior change science (i.e. behavior change principles or behavior change methods) are abstract, theoretical descriptions of how such natural psychological structures and processes can be leveraged to make certain changes.
For example, modelling relies on vicarious learning; the evolved learning process where organisms can learn through observation of other organisms. Because these behavior change principles leverage structures and functions that exist for very different reasons, correct application is a very delicate process.
To stick to the modeling example: modeling does not work when the audience does not identify with the used role model, or when the role model is not positively reinforced, or when it is a mastery model instead of a coping model, or when the audience does not have the requisite skills.
If one deviates from these parameters, the way the behavior change principle is applied in the intervention does not approximate the underlying evolved learning processes enough, and no learning will occur (in other words, the audience’s psyche will stay unchanged; and therefore, ultimately, so will their behavior).
In medicine, the analogy is found in things like dose (e.g. most medication has the desired effect at the right dose but does nothing at lower doses and can become toxic at higher doses) and molecular structure (e.g., benzylpenicillin or penicilin G treating syphilis and pneumonia with side effects including seizures, but phenoxymethylpenicillin or penicilin V treating otitis media with side effects including nausea).
Finally, in medicine, the mechanisms of action operate on specific structural or functional parts of the human body, lowering or increasing blood pressure, making blood thicker or thinner, or causing certain neurotransmitters to be released or inhibited. These dynamics are used to achieve a desirable state that should make the person more healthy.
In behavior change science, the mechanisms of action operate on specific structural or functional parts of the human psyche, lowering or increasing attitude, perceived norms, habits, or self-efficacy. These dynamics are used to achieve a desirable state that should make the person more healthy.
So, now the full causal-structural chain that underlies our model of why medication and interventions work is complete:
1️⃣ The mechanism of action [🧠 behavior change principle 🔄️ ⚕️pharmaceutical principle];
2️⃣ is applied [within its 🧠 parameters of use 🔄️ ⚕️ chemical constraints];
3️⃣ in a concrete implementation [🧠 practical applications 🔄️ ⚕️pills];
4️⃣ that targets specific elements [🧠 sub-determinants 🔁 ⚕️physiological variables];
5️⃣ that belong to an overarching cluster [🧠 determinants 🔁 ⚕️anatomical structure];
6️⃣ that causes an intermediate target [🧠 sub-behaviors 🔄️ ⚕️symptoms];
7️⃣ that is a part of the ultimate target [🧠target behavior 🔄️ ⚕️disease].