Individual Differences in Revising (and Maintaining) Accurate and Inaccurate Beliefs About Childhood Vaccinations

"[D]espite reading a refutational text on childhood vaccinations, readers' preexisting accurate and inaccurate beliefs significantly predicted postreading beliefs about childhood vaccinations."

Sources of information regarding vaccinations have shifted from traditional sources, such as doctors and physicians, to nontraditional sources, such as politicians, celebrities, the media, and others on the internet. Previous researchers have explored multiple methods for correcting the misconceptions and misinformation individuals may encounter in their quest to decide about vaccinating their child; fewer studies have explored differences in individual thinking dispositions that could contribute to correcting or revising misinformation. Preexisting beliefs about a controversial topic like childhood vaccinations may guide how deeply readers process available information and the understandings they develop. The present work seeks to strengthen and extend prior research on the influence of preexisting beliefs to examine their contributions to comprehending a text that refutes commonly endorsed misconceptions in favour of an accurate conception.

Two hundred and nineteen individuals (62.5% female) at a large university in the United States (US) participated in the study. They responded to 3 open-ended questions regarding their knowledge of vaccinations and then read a refutational text supporting childhood vaccinations. The text discussed controversial issues surrounding vaccinations, including claims of a link between vaccinations and autism spectrum disorder (ASD). Specifically, the text was constructed so that each paragraph began with an opening sentence stating one misconception about vaccinations, followed by a single sentence stating that the misconception is inaccurate, and then approximately 6 additional sentences designed to refute the targeted misconception. Participants were prompted to read the text with the goal of answering the question, "If you are a parent or were to become one, would you support vaccinating your own child?" They were asked to write an essay in response to this question.

Other components of the study:

• A 13-item Childhood Vaccination Belief Inventory (CVBI) measured participants' accurate beliefs that vaccinations are beneficial to a child's health (hereafter referred to as "helpfulness") and inaccurate beliefs that vaccinations are "harmful" or "unnecessary".
• Participants completed an 18-item need for cognition scale with statements designed to assess the degree to which an individual prefers to engage in cognitive tasks (I prefer complex to simple problems) in comparison to avoiding them (I only think as hard as I have to).
• A 10-item flexible thinking scale assessed the degree to which an individual prefers to think actively or openly (A person should always consider new possibilities) in comparison to avoiding this type of thinking (Changing your mind is a sign of weakness).

The study involved 3 time points:

1. Participants completed the CVBI during a mass testing session to assess preexisting vaccination beliefs.
2. On day 1, participants were asked to complete the prior knowledge measure and to read the text on vaccinations. The researchers administered a distractor task to ensure that information from the texts was no longer in working memory. After writing their essays, participants completed the CVBI again to measure potential changes to their vaccination beliefs.
3. Forty-eight hours after completing day 1, participants returned to the laboratory and wrote a second essay using the same "express your beliefs about childhood vaccines" prompt. Participants again completed the CVBI, completed the need for cognition and flexible thinking scales, and reported their gender and ethnicity.

The data suggested that readers increased endorsement of statements reflecting inaccurate beliefs - specifically, that vaccinations are harmful - from pretest to immediate and delayed time points, albeit with small effect sizes. However, readers did substantially decrease in their agreement with statements reflecting inaccurate beliefs that vaccinations are unnecessary from pretest to immediate, which was also present at a delay. Thus, even though harmful and unnecessary beliefs are both inaccurate, the two types of beliefs displayed very different results regarding belief revision.

The researchers explain: "Multiple regression analyses demonstrated belief consistency effects in that preexisting accurate and inaccurate beliefs stably predict their postreading counterparts. Above and beyond these effects, readers higher in need for cognition were more likely to gain accurate beliefs about childhood vaccination at immediate and delayed time points. However, a backfire effect was also observed such that readers higher in flexible thinking were more likely to gain inaccurate beliefs, with concomitant lower values on accurate beliefs; this effect was present immediately and at a delay. The findings confirm that people can display a strong 'myside bias' even when reading refutations, but that higher need for cognition affords opportunities for appropriate knowledge revision."

Thus, the study "raises the question of whether some readers, perhaps more flexible thinkers, are more susceptible to misinformation perspectives when reading on a controversial topic like childhood vaccinations, even if the misconceptions are presented as a means by which the author intends to help readers overcome problematic misinformation."

Based on the findings, the researchers offer some suggestions for future directions. For example:

• Classroom interventions could investigate strategies that promote a deeper evaluation of information that might protect some readers from gaining inaccurate beliefs from texts that are actually designed to refute those beliefs.
• Educational settings that facilitate cognitive development and enjoyment in thinking and learning could prompt the development of need for cognition; fostering the development of a higher need for cognition early on could protect children from misinformation in future learning, as they may be less likely to include inaccurate information in their mental representations as they learn.

They indicate that interventions should be targeted at early stages of belief, perhaps before actual misconceptions are developed. "Learning to rely on trustworthy sources of information could combat misinformation such that during the early stages of belief development (when first learning) readers would be guided by a need to confirm the information comes from a reliable source. Teaching future generations to be more critical when learning information may be one of the best ways to combat the influence of misinformation when reading since professional gatekeeping is essentially absent in major reading venues such as on the Internet."