Olivier Klein
@olivierklein.bsky.social
Professor of social psychology at Université libre de Bruxelles, Belgium. Daily 🚴 .
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Olivier Klein
@olivierklein.bsky.social
· Nov 17
The Psychology of Vaccination
Why do some people choose to be vaccinated and others do not? What is the difference between vaccine hesitancy and anti-vaccinism? What can social psychology tell us about attitudes towards vaccinatio...
www.routledge.com
As anti-vax RFK will become US health secretary, now may be a good time to read our little book on the psychology of vaccination. www.routledge.com/The-Psycholo...
Reposted by Olivier Klein
Shout-out to the best possible team of co-authors: Elisa Tognon, @kenzonera.bsky.social, @rritabajraktari.bsky.social, Vincent Yzerbyt, @olivierklein.bsky.social, and Klein Pit (who originally started this project).
OA here: onlinelibrary.wiley.com/doi/10.1002/...
OA here: onlinelibrary.wiley.com/doi/10.1002/...
The Impact of Freedom of Speech on Conspiracy Beliefs
Conspiracy beliefs are often portrayed as a threat to democracies. However, less is known about the extent to which the state of democracy may affect conspiracy beliefs. Hence, we investigated the im...
onlinelibrary.wiley.com
October 31, 2025 at 12:57 PM
Shout-out to the best possible team of co-authors: Elisa Tognon, @kenzonera.bsky.social, @rritabajraktari.bsky.social, Vincent Yzerbyt, @olivierklein.bsky.social, and Klein Pit (who originally started this project).
OA here: onlinelibrary.wiley.com/doi/10.1002/...
OA here: onlinelibrary.wiley.com/doi/10.1002/...
Reposted by Olivier Klein
A library director in Wyoming who was fired two years ago because she refused to remove books with sexual content and LGBTQ themes from a library's children and young adult sections has just been awarded $700,000 in a settlement. t.co/EA5L1kOZfV
https://www.nytimes.com/2025/10/09/us/wyoming-library-settlement-book-bans-terri-lesley.html?smtyp=cur&smid=fb-nytimes&fbclid=IwdGRjcANWLXdleHRuA2FlbQIxMQABHhlnY6nKj_j4zuP3VjNSstXWBaV1t8-sPQ5C3b_jS6WN...
t.co
October 11, 2025 at 4:15 PM
A library director in Wyoming who was fired two years ago because she refused to remove books with sexual content and LGBTQ themes from a library's children and young adult sections has just been awarded $700,000 in a settlement. t.co/EA5L1kOZfV
Reposted by Olivier Klein
Cinq ans après la pandémie de Covid-19, l’autorité chargée de la politique vaccinale aux États-Unis se réunit à New York. Mais elle est désormais composée d’opposants aux vaccins nommés par le premier d’entre eux, le ministre de la santé Robert Kennedy Jr. www.mediapart.fr/journal/inte...
États-Unis : les antivax prennent le pouvoir sur la santé
L’autorité sanitaire chargée de la politique vaccinale se réunit jeudi et vendredi à New York. Mais cinq ans après le début de la pandémie de covid-19, elle est désormais composée d’opposants aux vac…
www.mediapart.fr
September 18, 2025 at 8:21 PM
Cinq ans après la pandémie de Covid-19, l’autorité chargée de la politique vaccinale aux États-Unis se réunit à New York. Mais elle est désormais composée d’opposants aux vaccins nommés par le premier d’entre eux, le ministre de la santé Robert Kennedy Jr. www.mediapart.fr/journal/inte...
Reposted by Olivier Klein
Journal publishers *are* bundling your papers up in "data licensing agreements" for big tech companies to use for AI model training. Our publisher, T&F, got £75m from Microsoft for that last year alone.
September 6, 2025 at 11:14 PM
Journal publishers *are* bundling your papers up in "data licensing agreements" for big tech companies to use for AI model training. Our publisher, T&F, got £75m from Microsoft for that last year alone.
Reposted by Olivier Klein
Results so stunningly clear they inspired this classic xkcd (xkcd.com/2400/):
September 1, 2025 at 7:32 PM
Results so stunningly clear they inspired this classic xkcd (xkcd.com/2400/):
Reposted by Olivier Klein
Wow and wow and WE MUST ALL DO THIS!!
“Over the past 20 years, Paris has undergone a major physical transformation, trading automotive arteries for bike lanes, adding green spaces and eliminating 50,000 parking spaces.
Part of the payoff has been invisible — in the air itself.”
Leadership, strategy, real action, common sense. #Paris
Part of the payoff has been invisible — in the air itself.”
Leadership, strategy, real action, common sense. #Paris
Paris said au revoir to cars. Air pollution maps reveal a dramatic change.
Air pollution fell substantially as the city restricted car traffic and made way for parks and bike lanes.
www.washingtonpost.com
August 30, 2025 at 12:44 AM
Wow and wow and WE MUST ALL DO THIS!!
This post has not aged badly unfortunately.
As anti-vax RFK will become US health secretary, now may be a good time to read our little book on the psychology of vaccination. www.routledge.com/The-Psycholo...
The Psychology of Vaccination
Why do some people choose to be vaccinated and others do not? What is the difference between vaccine hesitancy and anti-vaccinism? What can social psychology tell us about attitudes towards vaccinatio...
www.routledge.com
August 29, 2025 at 1:19 AM
This post has not aged badly unfortunately.
Reposted by Olivier Klein
“Chicago has long helped to keep alive tiny fields & esoteric areas of humanistic study... Without the univ’s support, & the continued training of grad students who can keep these bodies of kn going, entire spheres of human learning might eventually blink out.” www.theatlantic.com/culture/arch...
If the University of Chicago Won’t Defend the Humanities, Who Will?
Why it matters that the University of Chicago is pausing admissions to doctoral programs in literature, philosophy, the arts, and languages
www.theatlantic.com
August 27, 2025 at 12:18 PM
“Chicago has long helped to keep alive tiny fields & esoteric areas of humanistic study... Without the univ’s support, & the continued training of grad students who can keep these bodies of kn going, entire spheres of human learning might eventually blink out.” www.theatlantic.com/culture/arch...
Reposted by Olivier Klein
Plus envie d'argumenter, plus envie de documenter. Tout est là, sous nos yeux. Mais comment faire prendre conscience de ce qu'est une famine?
August 23, 2025 at 8:03 PM
Plus envie d'argumenter, plus envie de documenter. Tout est là, sous nos yeux. Mais comment faire prendre conscience de ce qu'est une famine?
Reposted by Olivier Klein
My dept at the University of Auckland (NZ) will be hiring in social psych at the junior level this cycle. Official ad to follow
It's a big research-active dept with fun colleagues, plus you can commute to uni on a boat, paired with a pleasant walk thru Albert Park (this pic from heading home today)
It's a big research-active dept with fun colleagues, plus you can commute to uni on a boat, paired with a pleasant walk thru Albert Park (this pic from heading home today)
August 20, 2025 at 6:47 AM
My dept at the University of Auckland (NZ) will be hiring in social psych at the junior level this cycle. Official ad to follow
It's a big research-active dept with fun colleagues, plus you can commute to uni on a boat, paired with a pleasant walk thru Albert Park (this pic from heading home today)
It's a big research-active dept with fun colleagues, plus you can commute to uni on a boat, paired with a pleasant walk thru Albert Park (this pic from heading home today)
Reposted by Olivier Klein
As our kids go #BackToSchool, never forget that we ARE the traffic that we’re afraid of. If more kids walked, biked or rode transit to school, it would erase a massive number of car trips each day, and our kids would be safer, healthier and better at school. HT Ian Lockwood.
Spread the word.
Spread the word.
August 19, 2025 at 4:26 PM
As our kids go #BackToSchool, never forget that we ARE the traffic that we’re afraid of. If more kids walked, biked or rode transit to school, it would erase a massive number of car trips each day, and our kids would be safer, healthier and better at school. HT Ian Lockwood.
Spread the word.
Spread the word.
Reposted by Olivier Klein
[Job] The Policy Lab at @ulbruxelles.bsky.social seeks to recruit a postdoctoral researcher (full time, 2 years) in the framework of the project 'Metropolitan internet meets post-growth'
Deadline: 30 August
Deadline: 30 August
July 31, 2025 at 4:43 PM
[Job] The Policy Lab at @ulbruxelles.bsky.social seeks to recruit a postdoctoral researcher (full time, 2 years) in the framework of the project 'Metropolitan internet meets post-growth'
Deadline: 30 August
Deadline: 30 August
Reposted by Olivier Klein
New blog post! Calculating a correlation is easy enough. But let's say you calculated two of them and they happen to differ. What follows from that? Turns out there are too many moving parts for an easy answer.
www.the100.ci/2025/07/28/w...
www.the100.ci/2025/07/28/w...
What’s in a correlation?
Correlation may not imply causation, but let’s just ignore that for a second. Correlations are standardized effect size metrics and as such have some quirks by design. These are benign enough when you...
www.the100.ci
July 28, 2025 at 12:21 PM
New blog post! Calculating a correlation is easy enough. But let's say you calculated two of them and they happen to differ. What follows from that? Turns out there are too many moving parts for an easy answer.
www.the100.ci/2025/07/28/w...
www.the100.ci/2025/07/28/w...
Reposted by Olivier Klein
I'm quoted in this piece. In short: do not use ChatGPT or any generative AI as a “therapist.” It’s not sentient. It doesn’t care. It may even lead people toward harm. And nothing shared is protected by HIPAA or real privacy standards; it's fodder for the machine. www.dazeddigital.com/life-culture...
AI is transforming how we communicate in relationships
‘All I wanted was to feel seen, heard and understood by him, but instead, he was sending me a robot’s questions’
www.dazeddigital.com
July 26, 2025 at 10:23 PM
I'm quoted in this piece. In short: do not use ChatGPT or any generative AI as a “therapist.” It’s not sentient. It doesn’t care. It may even lead people toward harm. And nothing shared is protected by HIPAA or real privacy standards; it's fodder for the machine. www.dazeddigital.com/life-culture...
Reposted by Olivier Klein
"De grâce, que la Belgique ne réagisse pas trop tard. En commençant par manifester une indignation commune devant des menaces envers les magistrats, car cette indignation est le premier bouclier pour protéger les défenseurs de l’Etat."
Ils veulent assassiner un magistrat, indignons-nous
Ils veulent assassiner un magistrat, indignons-nous
La menace qui pèse actuellement sur la vie de Julien Moinil, procureur du Roi de Bruxelles, est de nature différente : ils veulent assassiner l’un des principaux visages de la lutte contre le narcotrafic. Et devant cette situation extrêmement choquante, quasi aucune réaction du monde politique.
www.lesoir.be
July 15, 2025 at 8:26 PM
"De grâce, que la Belgique ne réagisse pas trop tard. En commençant par manifester une indignation commune devant des menaces envers les magistrats, car cette indignation est le premier bouclier pour protéger les défenseurs de l’Etat."
Reposted by Olivier Klein
Clear advice from @catherinedevries.bsky.social on clear writing.
Who could argue with such solid advice? (he naively asks the internet)
Who could argue with such solid advice? (he naively asks the internet)
July 9, 2025 at 6:52 PM
Clear advice from @catherinedevries.bsky.social on clear writing.
Who could argue with such solid advice? (he naively asks the internet)
Who could argue with such solid advice? (he naively asks the internet)
Reposted by Olivier Klein
Is there a difference between falsification and refutation?
Popper used the former in the book about logic of scientific discovery and the latter in the last (conjecture and refutation). And I never understood the difference.
Popper used the former in the book about logic of scientific discovery and the latter in the last (conjecture and refutation). And I never understood the difference.
July 9, 2025 at 6:44 PM
Is there a difference between falsification and refutation?
Popper used the former in the book about logic of scientific discovery and the latter in the last (conjecture and refutation). And I never understood the difference.
Popper used the former in the book about logic of scientific discovery and the latter in the last (conjecture and refutation). And I never understood the difference.
Very sad to learn that Helen De Cruz, who had been a constant online presence for me on Twitter and then here, passed away. Read her last blog post. A little gem on what we leave to others.
June 29, 2025 at 6:01 AM
Very sad to learn that Helen De Cruz, who had been a constant online presence for me on Twitter and then here, passed away. Read her last blog post. A little gem on what we leave to others.
Reposted by Olivier Klein
La Pride de Budapest interdite par Orban.
Rien n’arrête les libertés.
Surtout pas le fascisme
Rien n’arrête les libertés.
Surtout pas le fascisme
June 28, 2025 at 3:35 PM
La Pride de Budapest interdite par Orban.
Rien n’arrête les libertés.
Surtout pas le fascisme
Rien n’arrête les libertés.
Surtout pas le fascisme
Reposted by Olivier Klein
Lucky BJSP, who has gained a wise, enthusiastic and witty new associate editor!
🎉Starting September 1st, I'll be an Associate Editor for the British Journal of Social Psychology (BJSP). It is a great honor! 🎉
I won't make jokes about bribery options to get your paper published through me, as I am not sure yet if I'm allowed to* and I don't want to be fired before I start. 1/2
I won't make jokes about bribery options to get your paper published through me, as I am not sure yet if I'm allowed to* and I don't want to be fired before I start. 1/2
June 24, 2025 at 10:08 PM
Lucky BJSP, who has gained a wise, enthusiastic and witty new associate editor!
Lucky BJSP, who has gained a wise, enthusiastic and witty new associate editor!
🎉Starting September 1st, I'll be an Associate Editor for the British Journal of Social Psychology (BJSP). It is a great honor! 🎉
I won't make jokes about bribery options to get your paper published through me, as I am not sure yet if I'm allowed to* and I don't want to be fired before I start. 1/2
I won't make jokes about bribery options to get your paper published through me, as I am not sure yet if I'm allowed to* and I don't want to be fired before I start. 1/2
June 24, 2025 at 10:08 PM
Lucky BJSP, who has gained a wise, enthusiastic and witty new associate editor!
Reposted by Olivier Klein
Great post on the many bad effects of measles. That Roald Dahl letter of his daughter's death gets me every time tho 😔
Measles causes more than an acute illness: it suppresses immune memory and increases the risk of complications for years.
Even in a typical case of measles, children who survive the infection recover slowly.
Even in a typical case of measles, children who survive the infection recover slowly.
June 16, 2025 at 1:07 PM
Great post on the many bad effects of measles. That Roald Dahl letter of his daughter's death gets me every time tho 😔
Reposted by Olivier Klein
Best image of the day:
June 15, 2025 at 2:30 AM
Best image of the day:
Reposted by Olivier Klein
"Simpson's gender-equality paradox" surely deserve some award for best title 👑
The gender-equality paradox seems really central to some narrative people have constructed (and successfully sold). I absolutely wouldn't be surprised if it turned out 100% confounding.>
www.pnas.org/doi/10.1073/...
The gender-equality paradox seems really central to some narrative people have constructed (and successfully sold). I absolutely wouldn't be surprised if it turned out 100% confounding.>
www.pnas.org/doi/10.1073/...
June 12, 2025 at 3:11 PM
"Simpson's gender-equality paradox" surely deserve some award for best title 👑
The gender-equality paradox seems really central to some narrative people have constructed (and successfully sold). I absolutely wouldn't be surprised if it turned out 100% confounding.>
www.pnas.org/doi/10.1073/...
The gender-equality paradox seems really central to some narrative people have constructed (and successfully sold). I absolutely wouldn't be surprised if it turned out 100% confounding.>
www.pnas.org/doi/10.1073/...