Register to ask Dr. Bo a question, or comment on any question/answer.

one moment please...

Bo takes a critical thinking-, reason-, and science-based approach to issues that matter with the goal of educating and entertaining. You create the show by submitting your questions here. Bo has a PhD in social psychology, but covers a broad range of topics including: Science Education (scientific method, what is / is not science, etc.), Success, Entrepreneurship, Motivation, General Psychology, Social Psychology, Positive Psychology (well-being, flourishing, happiness, etc.), Cognitive Psychology (belief, cognitive biases, memory, our flawed brain, etc.), General Social Science, Critical Thinking, Logical Fallacies, Humanism / Secularism, and even some Philosophy. All (reasonable) questions will be answered here, and some will be the material for the Dr. Bo Show.

The first two years of shows have been compiled into the book, Reason: Book I. This book is available in hardcover, ebook, and audiobook through Amazon and all major ebook retailers.

Q&A Home Contact Form

Send me a copy of this message
Send Message sending message...

Q&A Home Question



image loading...
Dudley Dowell
Mon, May 04, 2015 - 12:00 AM

Why are so many people against vaccines despite overwhelming support from the medical and scientific communities?

Quick Comment On This Question (no login required):
Your comment below will be anonymously sent to the question owner, it will not be posted, and you will not get a response.

Send Comment sending comment...

1 Answer



image loading...
Bo Bennett, PhD
Host, Doctor of Social Psychology


image loading...

Bo Bennett, PhD

Host, Doctor of Social Psychology


About Bo Bennett, PhD

I am the host of this show :) For my complete bio, please see
PrintMon, May 04, 2015 - 12:00 AM
With the measles outbreak at DisneyLand beginning in December of 2014, the debate on the need and safety of vaccines has been reignited. While I am not going to get into the science of vaccine safety and effectiveness, I am going to cover the psychology of the anti-vaccine movement, and some potential factors that lead to people denying scientific facts.

Out of Sight, Out of Mind

We tend not to think much about what we don't experience. For example, most of us (in the United States) take for granted that we have clean water to drink, adequate shelter, and the fact that we can criticize our President without getting shot. These are simply not issues that concern us and as a result, we spend very little cognitive energy on them. Likewise, we don't think about all the diseases we don't have thanks to vaccines, such as Smallpox, Diphtheria, Whooping cough, Measles, Neonatal tetanus, Hepatitis B, Tuberculosis, and Polio, but we do focus on the statistically rare problems we do see as a result of vaccines. Because of this, our mental calculation of the pros and cons of vaccines tends to be severely inaccurate.

The Availability Heuristic

Related to out of sight and out of mind, the availability heuristic is the mental shortcut one takes when forming an inaccurate view of reality based on what information is more readily available. For example, most people are more worried about dying in a plane crash than an automobile accident, even though by some estimates, you are 22 times more likely to die in an automobile accident. One of the reasons for this misplaced fear is the attention plane crashes get compared to automobile accidents. The more rare the event, the more attention (media, Hollywood, gossip, etc.) it is likely to get. Serious problems that are undoubtedly the result of a reaction to a vaccine are rare, a topic of great interest, and therefore both memorable and salient. It is this salience that leads to a highly biased evaluation of all the available information on vaccine safety, including the millions of cases of people who receive their vaccinations without any problems.

Emotional Appeals

A good emotional plea can be far more effective than a collection of facts and accurate data. Charities know this secret well and don't bombard potential donors with statistics on how many people die of starvation, but rather provide a picture of a single starving child and give that child a name, with a plea to help this one child. The fact that vaccines have prevented hundreds of millions of people from contracting the measles is of much less emotional value than a story told by two grieving parents that anyone with heart would empathize, of one beautiful child named Amy who died as a result of a rare negative reaction to the vaccine . Emotional appeals have strong effects on our perceptions, but no effects on the facts.

Sense of Control

Having children is both a wonderful, but terrifying process. Given all the possible things that can go wrong over which we have no control, those things which we can control comfort us. Autism Spectrum Disorder is a psychological condition in which there is no known cure and no known causes (despite what some may claim) that currently affects and estimated 1 out of 68 children. Believing one has control over autism can be a comforting thought, but it is nothing more than wishful thinking. The belief that the severity of autism can be reduced or even that autism can be prevented by foregoing a few shots contributes to motivated reasoning, or a method of reasoning based on one's motivations rather than facts.

The Appeal To Nature

The appeal to nature is a logical fallacy people make when they believe or suggest that "natural" is better than "unnatural," without evidence for the assertion. Besides the ambiguity involved in the terms, reality provides us with countless examples of things in nature that are deadly (viruses, volcanoes, many species of plants, etc.) and human-made things that are life-saving (dental care, climate control, surgery, etc.). Many who are against vaccines don't like the idea of putting "unnatural chemicals" or "toxins" in our bodies, by default associating the unnatural with "bad," regardless of any evidence supporting that association. This is simply fallacious reasoning.

The Post-Hoc Fallacy

The post-hoc fallacy is a common fallacy based on how we perceive the world. If one event proceeds another, we tend to make a causal attribution where none exists. Since the vast majority of vaccines (including MMR) are given before but close to the time when most psychologists could confidently diagnose a child with autism spectrum disorder (at around 18–24 months), it is understandable that parents' would be tempted to infer causality (i.e., the vaccine caused the autism). However, controlled studies are not subject to this bias, and the overwhelming scientific consensus shows no evidence for this causal connection.

The Confirmation Bias at Work

Once people have a reason to hold an anti-vaccination position, whether it is because they believe that they are protecting their children from harm, seeking justice against an evil industry, or being a hero by exposing a government conspiracy, the confirmation bias kicks in, and information supporting their position is sought out and information that disconfirms their position (i.e., science) is ignored. Selective exposure magnifies this process by allowing people to customize their news and get information only from those sources that agree with their position.

This is not meant to be an exhaustive list of the decision process when it comes to the level of support one has for vaccines; it is meant to showcase just some of the common thoughts of generally rational thinkers that lead to irrational conclusions. While there are many people who are anti-vaccine that are simply unaware of the facts and being fed anti-scientific misinformation, there are also those who are aware of the science and because of motivated reasoning, argue their anti-vaccine position even stronger (known as the backfire effect). People can change their minds and may eventually accept the scientific facts of vaccine safety, but with this issue especially, time is a luxury we don't have.
Bo Bennett, PhD
My Latest Book:
About Me:

Podcast Episode: The Psychology Behind the Anti-Vaccine Movement

Subscribe via iTunes! and please leave a review there if you like this podcast!

Quick Comment On This Answer (no login required):
Your comment below will be anonymously sent to the answer owner, it will not be posted, and you will not get a response.

Send Comment sending comment...

Registered User Comments

Richard Butler
Monday, October 05, 2015 - 10:49:55 AM
New to the site Bo, but have to say very interesting audio, and I look forward to listening to the other audio files you have.

Nice to find a person who has the background and education and is qualified enough to talk about these topics

Thanks my friend!

login to reply
0 replies
1 votes


Chad Whitney, RN
Tuesday, May 05, 2015 - 03:28:31 AM
Hello Dr. Bennett.

I am a registered nurse. I personally educate and vaccinate close to one hundred people each year during flu season. The vast majority of people I vaccinate are older than thirty-five. Prior to vaccination, I hand the patient a Centers for Disease Control and Prevention education pamphlet. A good majority of people do not read the pamphlet and simply accept the vaccine.

One rare adverse effect to influenza vaccination is Guillain-Barré Syndrome (GBS) - a disorder where the immune system damages the nerve cells, causing muscle weakness and sometimes paralysis. I have personally seen a diagnosed case of influenza-related Guillain-Barré Syndrome requiring ventilator support for respiratory paralysis.

I recently referenced the Centers for Disease Control and Prevention website and found no definitive numbers in terms of influenza-related GBS. Instead, I found the following:

GBS is rare. Medical events occur regardless of vaccination. The background rate for GBS in the U.S. is about 80 to 160 cases of GBS each week, regardless of vaccination (

I would rather people remain informed, especially when it comes to introducing immune-modulating substances into the body. However, the information from the CDC website appears slightly misleading. Is this an attempt to passively disarm the public?

Your thoughts?

login to reply
1 reply
1 votes


Bo Bennett, PhD
Tuesday, May 05, 2015 - 06:33:48 AM
Hi Chad! First off, thank you for the work you do. Not just with the vaccination, but nursing in general and devoting your life to reducing suffering and increasing health. :)

The information on the CDC website appears to be based on the latest research in the field (see, for example). As for the number of documented cases, the CDC is the source for those, so we can either believe them or not. One can be skeptical of the CDC when it comes to personal risks because, theoretically, if the CDC's performance is measured by national averages and lower disease nationally means more individual harm for an unfortunate few, then one could reason that the CDC would be motivated to underestimate individual risk as long as the result is increased health nationally. While the CDC "spinning" the data in such a way is plausible, falsifying the data is far less plausible given the checks and balances in place within science.

The balance between informing the public of known risks and creating an irrational panic or fear, is a tough one. For example, the two statements below use the same data (i.e., facts):

"On very rare occasions, they [people who get the flu shot] may develop GBS in the days or weeks after getting a vaccination."
"If you get a flue shot, you may develop GBS in the days or weeks after getting a vaccination, and could possibly die."

Both statements are true, but many would argue that the latter is unnecessarily fear inducing. This is why statistics is important. Along with a subjective statement that infers opinion as to the overall safety, there needs to be statistical data so people can assess the risk on their own—which the CDC provides. When I get on a plane, I don't want the pilot reminding me that "there is a chance that we will crash and you die a horrible death"; but I do want to know the odds of such a fate. Overall, I think the CDC does a good job at representing the most current findings in science as well as how they manage to communicate this data to the public.

login to reply
1 votes


Linda Williams
Monday, May 04, 2015 - 12:10:03 PM
As much as I love debating with you, I agree with you here. These young parents today have no idea of what it was like when you knew the risk of sending your children to school and any day, they could come home with the measles, chicken pox, mumps. I came home with all three. It must have been by the 3rd grade that I finally got all my shots and the diseases stopped!
My Grandson was among those who thought as you described, fearing to allow the vaccine to be is his daughters body. Thank God, he caved when his mother, sisters and I persuaded him to get her the shots.

login to reply
0 replies
1 votes


 Copyright 2017, Archieboy Holdings, LLC.