Older adults share more political misinformation. Here’s why.

University of Colorado at Boulder

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

Adults aged 55 and older are significantly more likely to share political misinformation than younger social media users. And it’s not because they’re unable to discern fake news from real news, according to new University of Colorado Boulder research.

The study of nearly 2,500 adults across the United States and Brazil found that the older people get, the more partisan they become — and that partisanship can muddy their judgment.

“We found that older people are more likely to believe as true and to share information that aligns with their party, whether that information is true or not,” said senior author Leaf Van Boven, professor in the Department of Psychology and Neuroscience at CU Boulder.

The study was a collaboration with Guilherme Ramos, assistant professor of marketing at the Rochester Institute of Technology.

It was published Nov. 3 in the Journal of Experimental Psychology: General.

Are older adults more gullible?

Numerous previous studies have shown that older adults spread more misinformation. One found that during the 2016 U.S. presidential election, Facebook users over the age of 65 shared almost seven times more fake news than adults under age 30. On Twitter, 80% of fake news was shared by users over age 50.

The reason remains a matter of debate.

Some research has pointed to age-related cognitive decline, suggesting that older adults are less able to think analytically and more vulnerable to being duped. Other studies show they are more likely to confuse the origin of a piece of information and often fail to distinguish paid ads from objective news.

In contrast, a recent meta-analysis of 31 studies concluded that older adults are better than young adults at spotting fake news.

In 2022, Van Boven and co-author Ramos, who was at CU as a visiting PhD student from the Brazilian School of Public and Business Administration (FGV-EBAPE) in Rio de Janeiro, decided to take a deeper look.

At the time, misinformation storms swirled across both countries around the upcoming midterms in the U.S. and the controversial runoff between presidential candidates Lula da Silva and Jair Bolsonaro in Brazil.

The researchers recruited 700 participants in Brazil and 1,700 in the U.S., ranging in age from 18 to 80.

Participants viewed news headlines related to political events in their country. Some painted Republican or conservative ideologies in a favorable light. Others favored Democrat or liberal ideologies. Unbeknownst to the participants, some headlines had been flagged by fact-checking websites to be false.

For instance, one widely circulating, false pro-Republican headline in the U.S. read:

“Pope Frances shocks world and endorses Donald Trump for President.”

A pro-liberal and false headline widely circulating in Brazil read:

“Bolsonaro wants to cut 25% of civil servants’ salaries.”

Participants were asked, “How likely would you be to share this news in your social media?” In a follow-up experiment, participants were also asked whether the claim was, to the best of their knowledge, true or false.

Researchers also assessed respondent’s political ideology and ability to “override their intuitions and think analytically.”

The trouble with partisanship

The research found no evidence that older adults are less able to think analytically and distinguish fake from real news.

It did find that the 55-and-older set was far more partisan and that partisanship shaped how critically they assessed headline accuracy.

“They had different standards of evaluating evidence depending on whether it reflected well on their side or not,” said Van Boven.

The study stopped short of concluding that older adults knowingly share fake news. Instead, the study suggests that older adults are more skeptical when the news is favorable to “the other side.” If it makes their candidate look good, “they tend to behave in a knee-jerk partisan fashion,” assume it’s true and share it, said Van Boven. The older people get, the stronger this reaction becomes.

Notably, this trend held true across political parties and across both the U.S. and Brazil, which currently has roughly 30 political parties.

“This suggests that the two-party system is not necessarily the issue here,” said Ramos. “People in Brazil behave in the same partisan way.”

Stepping out of the echo-chamber

Many interventions developed to combat misinformation have centered around helping people distinguish truth from fiction.

 “Our study suggests that it is equally important to encourage people to behave in a less politically partisan way when they are communicating on their social networks,” said Van Boven.

He recommends that people take a hard look at what, and how much, they are posting, and how their own partisanship may be influencing the way they vet headlines.

In addition, said Ramos, stop unfriending people you disagree with politically.

“As someone who studies political polarization, I am very much in favor of inter-group contact. It’s critical for a healthy democracy that we can talk to and have friends who think differently.”

---

Journal

Journal of Experimental Psychology General

DOI

10.1037/xge0001868 

Method of Research

Survey

Subject of Research

People

Article Title

The age of misinformation: Older people exhibit greater partisan bias in sharing and evaluating (mis)information accuracy.

Article Publication Date

3-Nov-2025

 

Plant protection products change the behaviour of non-target organisms

UFZ team demonstrates effects on pollinators and fish

Helmholtz Centre for Environmental Research - UFZ

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

The honeybee (Apis mellifera) served as the model organism for pollinating insects.

view more 

Credit: André Künzelmann / UFZ

The application of plant protection products in agriculture is subject to strict regulations. Nevertheless, organisms that are not the primary target of their use, so-called non-target organisms, inevitably come into contact with these substances and can potentially be harmed by them. "Wild bees and other pollinators can come into contact with quite high concentrations shortly after spraying. But animals in aquatic habitats are also at risk," says UFZ biologist Prof. Martin von Bergen, one of the two joint principal investigators. "Rainfall gradually washes plant protection products into the surrounding waters. They don't simply remain and only affect the area where they are applied."

The UFZ team selected a research approach in which pollinators and fish were analysed, which are model systems for effects of chemicals in the terrestrial and the aquatic habitats. The honeybee (Apis mellifera) was selected as a model organism for pollinators and the zebrafish (Danio rerio) for aquatic animals. The researchers focused on behavioural changes as a result of exposure to plant protection products. "Of course, plant protection products do not always have a lethal effect on non-target organisms. However, depending on the type of product, even low concentrations can damage their health or impair their behaviour in such a way that this can have a negative impact on the individual, the population and ultimately even on the biodiversity of the ecosystem," says Cassandra Uthoff, UFZ doctoral student and lead author of the study. "Although animal behaviour tests following exposure to low concentrations of chemicals are already included in the risk assessment of chemicals in some cases, these tests are not complex enough and are typically not mandatory."

The UFZ researchers, an interdisciplinary team from the fields of animal behaviour research, ecotoxicology, and biochemistry, focused on precisely these complex behavioural patterns. "We wanted to find out whether and to what extent these behavioural patterns change when exposed to insecticides, herbicides and fungicides. To do this, we exposed the model organisms to concentrations of plant protection products that actually occur in their respective habitats in the environment and analysed their behaviour," explains Cassandra Uthoff. In the honeybees, the researchers observed reduced foraging activity and altered nectar processing behaviour following treatment with the insecticide. Fungicides and herbicides, on the other hand, led to less intensive brood care behaviour. "Such behavioural changes, triggered by environmentally relevant concentrations of plant protection products, can impair the performance and maintenance of the colonies and ultimately also their pollination services," says Uthoff.

To test the effects of plant protection products on aquatic organisms, the researchers used a behaviour-based screening method in the zebrafish embryo model. This enables rapid testing of chemicals for neuroactivity effects, including altered learning and memory processes. In addition to individual exposure to the plant protection products, the fish embryos were also exposed to various concentrations of an insecticide-herbicide-fungicide mixture that has been found in small streams in Germany. The exposure caused clear and specific changes in their behaviour: If the concentration of the mixture was low, the fish embryos exhibited behaviour that would normally be triggered by the herbicide alone. At higher concentrations of the same mixture, however, this behaviour was not reinforced, but replaced: The fish larva now behaved in the same way as when exposed to the fungicide.

"The work also demonstrates that mixtures of co-occurring plant protection products have the capacity to alter organismal behaviour at environmentally relevant concentrations. This supports the concept that, to better protect animals in the environment, chemical regulations should set acceptable exposure levels based on cumulative risk”, says Prof. Tamara Tal, UFZ ecotoxicologist and co-head of the study.

"The effects that we were able to measure in these animal models suggest that the actual ecological effects of plant protection products are much more far-reaching than previously assumed", says Martin von Bergen.

The researchers are therefore calling for the integration of more relevant behavioural tests for low-concentration chemicals in the risk assessment frameworks for plant protection products. This would help to identify critical substances and better protect non-target organisms, thereby contributing to the preservation of biodiversity in agricultural landscapes.

---

DOI

10.1016/j.envint.2025.109750 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Cross-taxa sublethal impacts of plant protection products on honeybee in-hive and zebrafish swimming behaviours at environmentally relevant concentrations

 

Low-dose THC reduces side effects of HIV treatment

Texas Biomed researchers find promising benefits for gut health, serotonin levels and more. The study, reported in Science Advances, could have broad implications for other diseases linked to gut inflammation.

Texas Biomedical Research Institute

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

The number of active serotonin receptors (green) were dramatically increased in the lining of the gut following treatment with low-dose THC, which helps increase serotonin communication between the gut and the brain.

view more 

Credit: Texas Biomed

SAN ANTONIO (Nov. 6, 2025) – Long-term, low doses of THC mitigate many harmful side effects and inflammation caused by HIV and antiretroviral therapy (ART), according to new research from Texas Biomedical Research Institute.

THC is short for tetrahydrocannabinol, the main active compound in cannabis. The preclinical study used very low doses of THC, meaning the compounds don’t trigger overt nervous system effects such as euphoria, or a “high.”

The benefits included increased production of the chemical serotonin, while inflammation, cholesterol and harmful secondary bile acids were all reduced. Notably, levels of ART drugs, which can be toxic to the liver over time, were lower in blood plasma without affecting viral suppression. The detailed findings, made in animal models representing people with HIV on ART, were recently published in Science Advances.

Managing side effects

ART does a very good job at suppressing HIV to undetectable levels. Once a death sentence, HIV is now a manageable disease. But as people live longer with HIV, they are experiencing substantial side effects from the virus and the medications.

“People living with HIV experience chronic inflammation, which leads to many co-morbidities such as cardiovascular disease, liver disease and some neurological diseases,” said Professor Mahesh Mohan, DVM, Ph.D. “Our lab is interested in finding solutions to help address this.”

The current study builds on previous research in Dr. Mohan’s lab into therapeutic uses of low-dose THC – similar to FDA-approved THC medications for treating seizures, chemotherapy-induced nausea and vomiting, and AIDS-related anorexia and weight loss.

“No downsides”

Over the past three years, Lakmini Premadasa, Ph.D., a Staff Scientist in Dr. Mohan’s lab, analyzed hundreds of metabolites – small molecules that help carry out daily functions – to determine if this low-dose treatment given daily alongside ART benefited other parts of the body.

“There were no downsides,” Dr. Premadasa said. “I kept looking because I couldn’t believe it could all be good, but I really could not find any negative impacts.”

Lower ART-associated toxicity

For the study, two groups of rhesus macaques with simian immunodeficiency virus (SIV), the equivalent of HIV, were given ART for five months. One group also received low-dose THC, while the second group received a placebo. At five months, both groups had suppressed SIV to undetectable levels, but that is where the similarities stopped.

Notably, even though viral suppression was maintained, there were much lower levels of ART drugs circulating in the blood of the THC-treated group, compared to the group that only received ART.

“This was unexpected,” Dr. Premadasa said. “This suggests that THC is helping to metabolize the antiretroviral drugs faster, which is actually much better to protect the liver from toxicity associated with some currently prescribed ART drugs.”

Low-dose THC for a happy gut

Another key finding: serotonin, an important neurotransmitter that regulates mood along with a host of other functions, including sleep and digestion, was much higher in the THC-treated group compared to controls.

The increases were observed across multiple facets of serotonin production, which occurs primarily in the gut. Specifically, Dr. Premadasa found higher numbers of specialized enterochromaffin cells that produce serotonin and more good gut bacteria (L. plantarum) that facilitate serotonin production in the THC-treated group, compared to the control group. She also observed significant upregulation of serotonin receptors in the THC-treated group, which are required to convey signals from the gut to the brain via the vagus nerve, enhancing the gut-brain axis communication.

“This is an exciting finding that could be investigated further to address a range of conditions related to low serotonin levels, including depression, memory loss, brain fog and perhaps long-COVID symptoms,” Dr. Mohan said. “Reduced serotonin levels are known to disrupt signaling between the gut and brain, so improving those serotonin levels and communication with low-dose cannabinoids could offer a new or complementary treatment approach.”

More unexpected benefits

The THC-treated group also had a healthier, more balanced gut microbiome with higher levels of good gut bacteria, including species that help lower cholesterol. There were lower levels of secondary bile acids, which are toxic at high levels and can lead to blockage in the liver bile ducts (cholestasis), inflammation and scarring (cirrhosis) and end-stage liver disease.

Other metabolites were increased that help break down fatty acids, which helps reduce plaque that clogs arteries, thus improving cardiovascular health. In fact, levels of plaque-causing fatty acids, called long-chain acetylcholines, had returned to pre-infection levels in the THC-treated group, while the control group continued to have significantly elevated levels of harmful fatty acids.

Next steps

Since this work was completed in nonhuman primates, additional research is required to confirm if the same results occur in people. The results could also have implications for many other diseases linked to gut inflammation, such as irritable bowel syndrome, chronic liver disease and neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases.

The research team is now investigating the nonpsychoactive cannabidiol, or CBD, when it is combined with THC taken orally or in a shot alongside ART. The team also plans to research other minor cannabinoids and the aromatic compounds that give many plants their scents and flavors, called terpenes, in the future, as there is growing clinical interest in these compounds. The researchers caution that readers should not assume commercially available cannabinoid products offer the same benefits observed in this study because of the way different products are consumed and metabolized in the body. The best course of action is to consult with your healthcare provider before attempting any cannabinoid-based medications.

Paper:
Lakmini S. Premadasa et al., Supplementing HIV-ART with cannabinoids increases serotonin, BHB, and Ahr signaling while reducing secondary bile acids and acylcholines. Sci. Adv. 11, eadw4021(2025). DOI:10.1126/sciadv.adw4021

Funding:
National Institutes of Health award numbers R01DA042524 (M.M.) and R01DA052845 (M.M.), P30AI161943, P51OD011104 and P51OD111033.

###

About Texas Biomed:
Texas Biomed is a nonprofit research institute dedicated to protecting the global community from infectious diseases. Through basic research, preclinical testing and innovative partnerships, we accelerate diagnostics, therapies and vaccines for the world’s deadliest pathogens. Our San Antonio campus hosts high containment laboratories and the Southwest National Primate Research Center. Our scientists collaborate with industry and researchers globally and have helped deliver the first COVID-19 vaccine, the first Ebola treatment and first Hepatitis C therapy. For more information, please visit https://txbiomed.org. 

---

Journal

Science Advances

DOI

10.1126/sciadv.adw4021 

Article Title

Supplementing HIV-ART with cannabinoids increases serotonin, BHB and Ahr signaling while reducing secondary bile acids and acylcholines

 

Meta-analysis offers reassurance that pregnant women can safely use acetaminophen

Systematic review in the Journal of the American Academy of Child & Adolescent Psychiatry offers reassurance that acetaminophen use during pregnancy does not increase risk of neurodevelopmental disorders

Elsevier

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

November 6, 2025 – A rigorous systematic review of the present state of knowledge on the use of acetaminophen during pregnancy and the risk of specific neurodevelopmental disorders (NDDs), such as autism and ADHD, offers reassurance that acetaminophen does not increase the risk of NDDs. The study in the Journal of the American Academy of Child & Adolescent Psychiatry (JAACAP), published by Elsevier, points to methodological inadequacies in previous reviews and studies. It offers reassurance for pregnant women, public health agencies, and healthcare providers in alignment with recommendations from the Centers for Disease Control and Prevention (CDC), American College of Obstetricians and Gynecologists (ACOG), and The Society of Obstetricians and Gynecologists of Canada (SOGC).

Acetaminophen (paracetamol) is the most commonly used over-the-counter pain reliever during pregnancy, taken in an estimated 70% of all pregnancies. In 2021, a commentary about a possible increased risk of NDDs in children exposed to acetaminophen in utero was published, leading to substantial concerns in the general population and among prescribers. However, this publication—as well as a subsequent narrative review by the same group of researchers—was met with criticism of its methodology, choice and quality of studies considered, and lack of mechanistic data.

Acetaminophen exposure during pregnancy is difficult to assess in epidemiological studies because it is available over the counter without a prescription and is used as needed. Hence, there is inconsistency between studies regarding the risk of NDDs associated with its use in pregnancy.

“Given the significant methodological challenges in this area, additional individual studies will inevitably suffer the same limitations as are already present in published studies,” explains lead author of the current systematic review and meta-analysis Anick Bérard, PhD, University of Montreal and CHU Sainte-Justine, Montréal, Quebec, Canada. “An integrative approach, summarizing the present state of knowledge and quantifying specific methodological areas of biases, as our study does, is needed in order to have a significant impact in future studies performed as well as on the causal effect of acetaminophen use during pregnancy on the risk of specific NDDs.”

Dr. Bérard and an international group of experts in the field conducted a comprehensive search of major bibliographic databases and grey literature to identify human studies evaluating the association between prenatal acetaminophen exposure and the risk of NDDs in offspring. Sixteen studies retrieved met eligibility criteria. In the resulting novel systematic review and meta-analysis, the investigators applied rigorous systematic review methodologies to determine the extent to which current data can support an association between prenatal exposure to acetaminophen and the risk of NDDs in children. They also used quantitative bias analysis to provide an estimate of the direction, magnitude, and uncertainty arising from systematic errors when assessing acetaminophen use during pregnancy and the risk of ADHD in children and performed sensitivity analyses.

Dr. Bérard notes that while a modest but significant association between acetaminophen use during pregnancy and ADHD in children was initially observed, concerns about its reliability remain. She explains, "This association is unlikely to be explained by possible confounding factors that were assessed but were not seen when sibling controls (considered to be the most reliable study design for assessing this risk) were used."

The authors conclude that the observed increase in ADHD risk is likely not causal and can be explained by inherent biases and underlying genetic factors. They recommend further studies to examine this association more robustly.

Commenting on the study, noted expert in the field David Coghill, MD, Financial Markets Foundation Chair of Developmental Mental Health in the Departments of Paediatrics and Psychiatry at the University of Melbourne, observes, “This is a landmark study that highlights the importance of good science and strong methods. The findings of no association between acetaminophen use during pregnancy and the risk of autism and ADHD in the child are not unexpected. These new findings support the position of professional organizations and regulatory bodies around the world that women should continue to use acetaminophen during pregnancy and do so without fear. The fact that they contradict the recent announcements by the US government must be acknowledged and acted on.”

 

---

Journal

Journal of the American Academy of Child & Adolescent Psychiatry

DOI

10.1016/j.jaac.2025.09.031 

Method of Research

Systematic review

Subject of Research

People

Article Title

Systematic Review and Meta-Analysis: Acetaminophen Use During Pregnancy and the Risk of Neurodevelopmental Disorders in Childhood