The strange psychology of vaccine hesitancy

I have written about this very subject many years ago, but the current world situation prompts me to recapitulate it once again.

There is a quite strange psychological phenomenon, in some cases, where people have quite irrational attitudes towards the probability of themselves experiencing adverse health effects from a disease or from a vaccine against that disease.

Let's say, hypothetically, that a particular highly contagious disease has about a 2% mortality rate. In other words, if you get the disease, there's about a 2% chance that you'll die from it.

Then, let's say that there's a vaccine against that disease that pretty much effectively stops you from dying of it, but the vaccine itself has about a 0.002% of killing you.

Many, many people would vehemently oppose getting the vaccine and prefer taking their 2% chance with the disease. It doesn't matter how well they are explained the odds, and how well they understand the odds, they still will refuse to take the vaccine, and instead take their chances with the disease itself. Even though they know there's a thousand times higher chance of dying.

Why? This is a very curious and complicated psychological phenomenon.

Moreover, assume that that 0.002% figure was just rumor, not based on any actual medical scientific research and statistics. In other words, there's quite a high chance that it's completely bogus, and that the vaccine doesn't actually kill anybody.

Many of these people would still strongly hesitate to take the vaccine. Just the idea that there could perhaps be a chance that they will die from it will make them hesitate, no matter how low the chances and how unfounded the claims.

Quite often these people don't have strong doubts about the death toll of the disease itself, and acknowledge that it does indeed kill people in a significant amount. Yet they still hesitate to take the vaccine if it's even rumored that maybe there's a really small chance of killing you.

It doesn't end there.

Suppose that there's some indication that an extremely small percentage of people have some severe adverse, but not lethal, side-effects to the vaccine. Like, for example, about one in a million vaccinated people might experience severe adverse side-effects that are worse than just your typical vaccine side-effects (pain where the vaccine was administered for a couple of days, maybe feverish feelings), such as chronic hand tremor that lasts for months, inflammation of the testicles, or other similar adverse effects.

Again, this causes hesitancy in many people, even though they know how small the chances are, and how big the chances are that the disease itself will cause severe side-effects (all the way up to including death) with a much higher probability. For example the disease may require hospitalization in an intensive care unit, and may cause eg. lung damage that will take months or even years to heal, if it ever heals completely.

Indeed, many of these people are willing to take their chances with the disease itself rather than take the vaccine, no matter how low the chances of adverse side-effects are with the latter.

As you might have discerned, this is not actually just a hypothetical situation. It's the current actual real-life situation with covid-19 and the vaccine.

But why? What is the psychological phenomenon behind this?

I believe that this is a deeply ingrained primitive instinct in the human psyche which contrasts harming oneself via direct action, vs. harm coming to oneself passively, ie. not caused by one's direct action.

The deeply ingrained primitive instinct is that if a disease causes you harm, it wasn't your fault. You didn't directly and actively do anything to harm yourself, and therefore you are not to blame, and it's not shameful. After all, you can't really control if you get a disease, like the common cold, or influenza. It's not your fault. It just happens. There's no shame in it.

However, the same instinct contrasts this with the idea of harm coming to you via your own direct willing action. You actively did something, and that something caused you severe harm. You are the culprit in this process. You were the dumbass who did the thing, and it backfired on you. It's shameful and embarrassing.

So my hypothesis is that this vaccine hesitancy psychological phenomenon, which goes against all odds and all rationality, is closely related to the deeply ingrained instincts that cause and avoid feelings of shame and embarrassment in the eyes of others (even if it doesn't happen at the conscious level): You are a dumbass and worthy of ridicule in the eyes of others if you directly and actively did something that caused you harm, but you are just an innocent blameless victim if the harm came to you for no action of your own, and thus there's no shame in it.

This is not necessarily a question of actual shame and embarrassment, but I believe it's the same innate deeply ingrained instinct in our brains that's in play here.

All rational thought, all the numbers and the math, go out the window when we are talking about primitive innate instincts.