Julien Mayor
@julienmayor.bsky.social
Developmental Scientist - how are babies learning languages?
Word learning, infant speech perception, language assessments and open science.
https://www.sv.uio.no/psi/english/people/academic/julienma/index.html
Word learning, infant speech perception, language assessments and open science.
https://www.sv.uio.no/psi/english/people/academic/julienma/index.html
New paper challenging the didactic role of Infant-Directed Speech (IDS)
We hypothesised that parents use IDS as a didactic tool by acoustically emphasising unknown words.
Analysing 38k speech segments (182 parents of 8-18m olds)
=> NO evidence for a didactic strategy!
doi.org/10.1037/dev0002077
We hypothesised that parents use IDS as a didactic tool by acoustically emphasising unknown words.
Analysing 38k speech segments (182 parents of 8-18m olds)
=> NO evidence for a didactic strategy!
doi.org/10.1037/dev0002077
November 12, 2025 at 7:51 PM
New paper challenging the didactic role of Infant-Directed Speech (IDS)
We hypothesised that parents use IDS as a didactic tool by acoustically emphasising unknown words.
Analysing 38k speech segments (182 parents of 8-18m olds)
=> NO evidence for a didactic strategy!
doi.org/10.1037/dev0002077
We hypothesised that parents use IDS as a didactic tool by acoustically emphasising unknown words.
Analysing 38k speech segments (182 parents of 8-18m olds)
=> NO evidence for a didactic strategy!
doi.org/10.1037/dev0002077
My wonderful colleague Natalia Kartushina has a PhD opening to study the role of early accent exposure in children's cognitive and language development!
Don't miss it!
www.jobbnorge.no/en/available...
Don't miss it!
www.jobbnorge.no/en/available...
Doctoral Research Fellowship in Developmental Psycholinguistics (286187) | University of Oslo
Job title: Doctoral Research Fellowship in Developmental Psycholinguistics (286187), Employer: University of Oslo, Deadline: Friday, November 14, 2025
www.jobbnorge.no
September 22, 2025 at 11:48 AM
My wonderful colleague Natalia Kartushina has a PhD opening to study the role of early accent exposure in children's cognitive and language development!
Don't miss it!
www.jobbnorge.no/en/available...
Don't miss it!
www.jobbnorge.no/en/available...
Reposted by Julien Mayor
Is anyone talking about the big design flaws in this study, e.g. 1) small N, btwn subject design, 2) v. heterogeneous sample, 3) writing prompt confounded with condition (really!), 4) vast number of measures with no preregistration?
I can't believe this is getting so much press...
I can't believe this is getting so much press...
ChatGPT May Be Eroding Critical Thinking Skills, According to a New MIT Study
ChatGPT May Be Eroding Critical Thinking Skills, According to a New MIT Study
Does ChatGPT harm critical thinking abilities? A new study from researchers at MIT’s Media Lab has returned some concerning results. The study divided 54 subjects—18 to 39 year-olds from the Boston ar...
themessengernews.com
June 20, 2025 at 3:01 PM
Is anyone talking about the big design flaws in this study, e.g. 1) small N, btwn subject design, 2) v. heterogeneous sample, 3) writing prompt confounded with condition (really!), 4) vast number of measures with no preregistration?
I can't believe this is getting so much press...
I can't believe this is getting so much press...
Reposted by Julien Mayor
Friends, I have news.
It is very good news.
You'll just have to read it, I'm afraid.
jamesclaims.substack.com/p/introducin...
It is very good news.
You'll just have to read it, I'm afraid.
jamesclaims.substack.com/p/introducin...
Introducing the Medical Evidence Project
And the quest to make less dead people
jamesclaims.substack.com
June 4, 2025 at 2:32 AM
Friends, I have news.
It is very good news.
You'll just have to read it, I'm afraid.
jamesclaims.substack.com/p/introducin...
It is very good news.
You'll just have to read it, I'm afraid.
jamesclaims.substack.com/p/introducin...
Reposted by Julien Mayor
Our meta-meta-analysis is officially out! (w/ Molly Lewis, Sho Tsuji, @chbergma.bsky.social, @acristia.bsky.social, and @mcxfrank.bsky.social!)
Estimating age-related change in infants’ linguistic and cognitive development using (meta-)meta-analysis
onlinelibrary.wiley.com/doi/10.1111/...
Estimating age-related change in infants’ linguistic and cognitive development using (meta-)meta-analysis
onlinelibrary.wiley.com/doi/10.1111/...
Estimating Age‐Related Change in Infants' Linguistic and Cognitive Development Using (Meta‐)Meta‐Analysis
Developmental psychology focuses on how psychological constructs change with age. In cognitive development research, however, the specifics of this emergence is often underspecified. Researchers ofte...
onlinelibrary.wiley.com
May 12, 2025 at 5:51 PM
Our meta-meta-analysis is officially out! (w/ Molly Lewis, Sho Tsuji, @chbergma.bsky.social, @acristia.bsky.social, and @mcxfrank.bsky.social!)
Estimating age-related change in infants’ linguistic and cognitive development using (meta-)meta-analysis
onlinelibrary.wiley.com/doi/10.1111/...
Estimating age-related change in infants’ linguistic and cognitive development using (meta-)meta-analysis
onlinelibrary.wiley.com/doi/10.1111/...
Reposted by Julien Mayor
My editorial on how journals can earn trust.
We often use journal names as proxies for quality. This is bad bc it’s not valid. But it could be. Editors could make journal name a valid signal. And we could place value on journals that show us how they do that.
journals.sagepub.com/doi/full/10....
We often use journal names as proxies for quality. This is bad bc it’s not valid. But it could be. Editors could make journal name a valid signal. And we could place value on journals that show us how they do that.
journals.sagepub.com/doi/full/10....
May 8, 2025 at 9:25 AM
My editorial on how journals can earn trust.
We often use journal names as proxies for quality. This is bad bc it’s not valid. But it could be. Editors could make journal name a valid signal. And we could place value on journals that show us how they do that.
journals.sagepub.com/doi/full/10....
We often use journal names as proxies for quality. This is bad bc it’s not valid. But it could be. Editors could make journal name a valid signal. And we could place value on journals that show us how they do that.
journals.sagepub.com/doi/full/10....
Forget just birth order for early language!
(it's kinda U-shaped anyway...)
We introduce a *better* measure (capturing more variance): a household "child-to-caregiver" ratio, where old-enough siblings are considered caregivers, rather than being another child competing for parental resources.
1/
(it's kinda U-shaped anyway...)
We introduce a *better* measure (capturing more variance): a household "child-to-caregiver" ratio, where old-enough siblings are considered caregivers, rather than being another child competing for parental resources.
1/
Do older siblings help or hinder language development? And does it matter if they’re sisters or brothers? In our new paper we revisit the "birth order effect"... and took it a step further! w/ @julienmayor.bsky.social, Nora Serres and Natalia Kartushina 🙌 🧵 1/ #DevSci #langsky #devpsy
<em>Child Development</em> | SRCD Journal | Wiley Online Library
Growing up with multiple siblings might negatively affect language development. This study examined the associations between birth order, sibling characteristics and parent-reported vocabulary size i....
doi.org
May 6, 2025 at 12:40 PM
Forget just birth order for early language!
(it's kinda U-shaped anyway...)
We introduce a *better* measure (capturing more variance): a household "child-to-caregiver" ratio, where old-enough siblings are considered caregivers, rather than being another child competing for parental resources.
1/
(it's kinda U-shaped anyway...)
We introduce a *better* measure (capturing more variance): a household "child-to-caregiver" ratio, where old-enough siblings are considered caregivers, rather than being another child competing for parental resources.
1/
Reposted by Julien Mayor
🚨🚨🚨 I'm hiring a Postdoc for a 3-year position to come work with me at the University of Oslo using iterative learning experiments to understand the evolution of sound symbolism. Please share widely.
🔴 Deadline is May 31st '25
⏲️ Desired starting date is Fall '25
shorturl.at/vSTZx
🔴 Deadline is May 31st '25
⏲️ Desired starting date is Fall '25
shorturl.at/vSTZx
Postdoctoral Research Fellow connected to "ICONIC" (277523) | University of Oslo
Job title: Postdoctoral Research Fellow connected to "ICONIC" (277523), Employer: University of Oslo, Deadline: Saturday, May 31, 2025
shorturl.at
March 20, 2025 at 9:27 AM
🚨🚨🚨 I'm hiring a Postdoc for a 3-year position to come work with me at the University of Oslo using iterative learning experiments to understand the evolution of sound symbolism. Please share widely.
🔴 Deadline is May 31st '25
⏲️ Desired starting date is Fall '25
shorturl.at/vSTZx
🔴 Deadline is May 31st '25
⏲️ Desired starting date is Fall '25
shorturl.at/vSTZx
One more week to apply for the Associate Professor position in Developmental Psychology!
Great opportunity to join us in Oslo - academic freedom and easy access to nature...
#DevSci
#devpsy
#openscience
Great opportunity to join us in Oslo - academic freedom and easy access to nature...
#DevSci
#devpsy
#openscience
*** JOB ALERT ***
Tenured Associate Professor position in Developmental Psychology at the University of Oslo.
www.jobbnorge.no/en/available...
Deadline: March 3rd, 2025.
Please reach out in DM for details and repost widely!
#openscience experience a plus!
#DevSci
#devpsy
Tenured Associate Professor position in Developmental Psychology at the University of Oslo.
www.jobbnorge.no/en/available...
Deadline: March 3rd, 2025.
Please reach out in DM for details and repost widely!
#openscience experience a plus!
#DevSci
#devpsy
Associate Professor in Developmental Psychology (273166) | University of Oslo
Job title: Associate Professor in Developmental Psychology (273166), Employer: University of Oslo, Deadline: Monday, March 3, 2025
www.jobbnorge.no
February 24, 2025 at 2:04 PM
One more week to apply for the Associate Professor position in Developmental Psychology!
Great opportunity to join us in Oslo - academic freedom and easy access to nature...
#DevSci
#devpsy
#openscience
Great opportunity to join us in Oslo - academic freedom and easy access to nature...
#DevSci
#devpsy
#openscience
Reposted by Julien Mayor
New article! On a certain plutocrat invading our government to steal our future: sarahkendzior.substack.com/p/the-miners
The Miners
The men who would strip the future for parts.
sarahkendzior.substack.com
February 8, 2025 at 2:39 PM
New article! On a certain plutocrat invading our government to steal our future: sarahkendzior.substack.com/p/the-miners
Reposted by Julien Mayor
We also just announced a position for artificial intelligence in psychology www.jobbnorge.no/en/available... There were a few years that not much was announced, but things have picked up a little bit more recently
Associate Professor - Artificial Intelligence in Psychology (273074) | University of Oslo
Job title: Associate Professor - Artificial Intelligence in Psychology (273074), Employer: University of Oslo, Deadline: Monday, March 17, 2025
www.jobbnorge.no
January 21, 2025 at 2:40 PM
We also just announced a position for artificial intelligence in psychology www.jobbnorge.no/en/available... There were a few years that not much was announced, but things have picked up a little bit more recently
Reposted by Julien Mayor
Our department has just announced a new permanent associate professor position in developmental psychology, come join us at @uio.no! www.jobbnorge.no/en/available...
January 21, 2025 at 1:33 PM
Our department has just announced a new permanent associate professor position in developmental psychology, come join us at @uio.no! www.jobbnorge.no/en/available...
*** JOB ALERT ***
Tenured Associate Professor position in Developmental Psychology at the University of Oslo.
www.jobbnorge.no/en/available...
Deadline: March 3rd, 2025.
Please reach out in DM for details and repost widely!
#openscience experience a plus!
#DevSci
#devpsy
Tenured Associate Professor position in Developmental Psychology at the University of Oslo.
www.jobbnorge.no/en/available...
Deadline: March 3rd, 2025.
Please reach out in DM for details and repost widely!
#openscience experience a plus!
#DevSci
#devpsy
Associate Professor in Developmental Psychology (273166) | University of Oslo
Job title: Associate Professor in Developmental Psychology (273166), Employer: University of Oslo, Deadline: Monday, March 3, 2025
www.jobbnorge.no
January 20, 2025 at 1:57 PM
*** JOB ALERT ***
Tenured Associate Professor position in Developmental Psychology at the University of Oslo.
www.jobbnorge.no/en/available...
Deadline: March 3rd, 2025.
Please reach out in DM for details and repost widely!
#openscience experience a plus!
#DevSci
#devpsy
Tenured Associate Professor position in Developmental Psychology at the University of Oslo.
www.jobbnorge.no/en/available...
Deadline: March 3rd, 2025.
Please reach out in DM for details and repost widely!
#openscience experience a plus!
#DevSci
#devpsy
Reposted by Julien Mayor
We're still seeking candidates interested in causal inference and/or survival analysis for a postdoc position in Oslo. Deadline January 31.
Please apply or forward this to anyone who might be interested!
www.jobbnorge.no/en/available...
Please apply or forward this to anyone who might be interested!
www.jobbnorge.no/en/available...
Four year postdoc position at the Oslo Centre for Biostatistics and Epidemiology (OCBE) (272144) | University of Oslo
Job title: Four year postdoc position at the Oslo Centre for Biostatistics and Epidemiology (OCBE) (272144), Employer: University of Oslo, Deadline: Friday, January 31, 2025
www.jobbnorge.no
January 20, 2025 at 8:47 AM
We're still seeking candidates interested in causal inference and/or survival analysis for a postdoc position in Oslo. Deadline January 31.
Please apply or forward this to anyone who might be interested!
www.jobbnorge.no/en/available...
Please apply or forward this to anyone who might be interested!
www.jobbnorge.no/en/available...
Further evidence (this time with consonants) that, from an acoustic point of view, infant-directed speech (IDS) does not offer infants with a cleaner signal!
#DevSci
#langsky
#devpsy
#DevSci
#langsky
#devpsy
New paper out! Following from our work on vowels and prosody in infant-directed speech, we turned our attention to features of consonants and their role in language development. Great collab (as always!) w/ @julienmayor.bsky.social, Nina Varjola and Natalia Kartushina 🧵 1/ #DevSci #langsky #devpsy
Longitudinal changes in consonant production in infant-directed speech and infants’ early speech production from 6 to 12 months
Previous research suggests that acoustic features of infant-directed speech (IDS) might be beneficial for infants’ language development. However, cons…
www.sciencedirect.com
January 10, 2025 at 11:38 AM
Interested in doing a PhD on language acquisition in Oslo?
Check application process: www.jobbnorge.no/en/available... and feel free to reach out for more information!
PS. We have a nice growing community including Natalia Kartushina, Luca Onnis, @audunrosslund.bsky.social, and many more!
Check application process: www.jobbnorge.no/en/available... and feel free to reach out for more information!
PS. We have a nice growing community including Natalia Kartushina, Luca Onnis, @audunrosslund.bsky.social, and many more!
Doctoral research fellowships in linguistics and verbal communication (272418) | University of Oslo
Job title: Doctoral research fellowships in linguistics and verbal communication (272418), Employer: University of Oslo, Deadline: Friday, February 28, 2025
www.jobbnorge.no
December 18, 2024 at 2:43 PM
Interested in doing a PhD on language acquisition in Oslo?
Check application process: www.jobbnorge.no/en/available... and feel free to reach out for more information!
PS. We have a nice growing community including Natalia Kartushina, Luca Onnis, @audunrosslund.bsky.social, and many more!
Check application process: www.jobbnorge.no/en/available... and feel free to reach out for more information!
PS. We have a nice growing community including Natalia Kartushina, Luca Onnis, @audunrosslund.bsky.social, and many more!
Reposted by Julien Mayor
Three ManyBabies projects - big collaborative replications of infancy phenomena - wrapped up this year. The first paper came out this fall. I thought I'd take this chance to comment on what I make of the non-replication result. 🧵
bsky.app/profile/laur...
bsky.app/profile/laur...
The Manybabies4 paper is out! Infants' Social Evaluation of Helpers and Hinderers: A Large-Scale, Multi-Lab, Coordinated Replication Study onlinelibrary.wiley.com/doi/abs/10.1... 1000 babies tested in 37 labs; "Overall, 49.34% of infants preferred Helpers over Hinderers in the social condition"
Infants’ Social Evaluation of Helpers and Hinderers: A Large‐Scale, Multi‐Lab, Coordinated Replication Study
Evaluating whether someone's behavior is praiseworthy or blameworthy is a fundamental human trait. A seminal study by Hamlin and colleagues in 2007 suggested that the ability to form social evaluatio...
onlinelibrary.wiley.com
December 3, 2024 at 11:56 PM
Three ManyBabies projects - big collaborative replications of infancy phenomena - wrapped up this year. The first paper came out this fall. I thought I'd take this chance to comment on what I make of the non-replication result. 🧵
bsky.app/profile/laur...
bsky.app/profile/laur...
Heroic effort collecting, processing and analysing this longitudinal dataset of infant-directed speech...
Watch @audunrosslund.bsky.social space for more exciting results on how IDS relates to infant language development!
Watch @audunrosslund.bsky.social space for more exciting results on how IDS relates to infant language development!
12 months of data collection, 317 lab sessions, 22,958 phrases, 54,594 vowels, and a gazillion supplementary tables later... proud to say that our longitudinal study on the acoustics of infant-directed speech is now out! 👶🧵 1/ #DevSci #langsky #devpsy
royalsocietypublishing.org/doi/10.1098/...
royalsocietypublishing.org/doi/10.1098/...
A longitudinal investigation of the acoustic properties of infant-directed speech from 6 to 18 months | Royal Society Open Science
Caregivers often modulate their speech when interacting with infants, adapting a register
that has been suggested to have attentional, affective and didactic purposes. The
present preregistered study ...
royalsocietypublishing.org
November 29, 2024 at 2:08 PM
Heroic effort collecting, processing and analysing this longitudinal dataset of infant-directed speech...
Watch @audunrosslund.bsky.social space for more exciting results on how IDS relates to infant language development!
Watch @audunrosslund.bsky.social space for more exciting results on how IDS relates to infant language development!
Reposted by Julien Mayor
🚨Publication Alert!🚨
The ManyBabies4 paper is out! 37 labs around the world tested over 1,000 babies in the largest investigation of infants' social evaluation to date.
doi.org/10.1111/desc...
The ManyBabies4 paper is out! 37 labs around the world tested over 1,000 babies in the largest investigation of infants' social evaluation to date.
doi.org/10.1111/desc...
Infants’ Social Evaluation of Helpers and Hinderers: A Large‐Scale, Multi‐Lab, Coordinated Replication Study
Evaluating whether someone's behavior is praiseworthy or blameworthy is a fundamental human trait. A seminal study by Hamlin and colleagues in 2007 suggested that the ability to form social evaluatio...
doi.org
November 27, 2024 at 7:05 PM
🚨Publication Alert!🚨
The ManyBabies4 paper is out! 37 labs around the world tested over 1,000 babies in the largest investigation of infants' social evaluation to date.
doi.org/10.1111/desc...
The ManyBabies4 paper is out! 37 labs around the world tested over 1,000 babies in the largest investigation of infants' social evaluation to date.
doi.org/10.1111/desc...
Reposted by Julien Mayor
Can't get enough of infant habituation designs!?💥 In our new paper, @julienmayor.bsky.social, Alex Cristia, Natalia Kartushina and I tested native and non-native vowel discrimination in 6-month-old Norwegian infants using eye-tracking. 👶👀 1/
Native and non-native vowel discrimination in 6-month-old Norwegian infants
In the current preregistered study, we tested n = 67 6-month-old Norwegian infants’ discrimination of a native vowel contrast /y-i/ and a non-native (…
www.sciencedirect.com
October 24, 2024 at 1:34 PM
Can't get enough of infant habituation designs!?💥 In our new paper, @julienmayor.bsky.social, Alex Cristia, Natalia Kartushina and I tested native and non-native vowel discrimination in 6-month-old Norwegian infants using eye-tracking. 👶👀 1/
Reposted by Julien Mayor
Clinical Researchers:
I am here to warn you about a meteor hurling towards us.
That meteor represents increasing scrutiny of clinical research; and in particular how we approach data collection, analysis, interpretation and reporting.
Prepare now, or face the consequences.
1/
I am here to warn you about a meteor hurling towards us.
That meteor represents increasing scrutiny of clinical research; and in particular how we approach data collection, analysis, interpretation and reporting.
Prepare now, or face the consequences.
1/
October 24, 2024 at 7:49 AM
Clinical Researchers:
I am here to warn you about a meteor hurling towards us.
That meteor represents increasing scrutiny of clinical research; and in particular how we approach data collection, analysis, interpretation and reporting.
Prepare now, or face the consequences.
1/
I am here to warn you about a meteor hurling towards us.
That meteor represents increasing scrutiny of clinical research; and in particular how we approach data collection, analysis, interpretation and reporting.
Prepare now, or face the consequences.
1/
Reposted by Julien Mayor
🚨 New paper! 🚨 Myself, @julienmayor.bsky.social and Natalia Kartushina investigated the relationship between shared reading, screen time, and vocabulary size in n=1,442 Norwegian infants from diverse SES backgrounds. Spoiler alert: Get out those books! 📚👶 1/5
Associations between shared book reading, daily screen time and infants’ vocabulary size | Journal of Child Language | Cambridge Core
Associations between shared book reading, daily screen time and infants’ vocabulary size
www.cambridge.org
September 20, 2024 at 2:10 PM
🚨 New paper! 🚨 Myself, @julienmayor.bsky.social and Natalia Kartushina investigated the relationship between shared reading, screen time, and vocabulary size in n=1,442 Norwegian infants from diverse SES backgrounds. Spoiler alert: Get out those books! 📚👶 1/5
On my way to the Workshop on Infant Language Development - so excited that I realised I have my kids clothes in my luggage, except they aren’t with me on this trip…
I guess the only thing to do is to go #WILD ?
#parenting
I guess the only thing to do is to go #WILD ?
#parenting
June 18, 2024 at 3:30 PM
On my way to the Workshop on Infant Language Development - so excited that I realised I have my kids clothes in my luggage, except they aren’t with me on this trip…
I guess the only thing to do is to go #WILD ?
#parenting
I guess the only thing to do is to go #WILD ?
#parenting
Many thanks @chbergma.bsky.social and @helenahartmann.bsky.social for making the "big team science" panel discussion such a great event!
That was such a great event, thanks to everyone involved. And let me share here what was one of my closing messages: Why haven't you been part of a big team science project yet?
I cannot wait for your panel discussion on "Big Team" science!
Join us tomorrow at NORRN's 3rd annual conference (www.norrn.no for details - and please ignore the automatic caption below saying "danish"!!!)
Join us tomorrow at NORRN's 3rd annual conference (www.norrn.no for details - and please ignore the automatic caption below saying "danish"!!!)
June 4, 2024 at 6:10 PM
Many thanks @chbergma.bsky.social and @helenahartmann.bsky.social for making the "big team science" panel discussion such a great event!
Reposted by Julien Mayor
That was such a great event, thanks to everyone involved. And let me share here what was one of my closing messages: Why haven't you been part of a big team science project yet?
I cannot wait for your panel discussion on "Big Team" science!
Join us tomorrow at NORRN's 3rd annual conference (www.norrn.no for details - and please ignore the automatic caption below saying "danish"!!!)
Join us tomorrow at NORRN's 3rd annual conference (www.norrn.no for details - and please ignore the automatic caption below saying "danish"!!!)
June 4, 2024 at 11:05 AM
That was such a great event, thanks to everyone involved. And let me share here what was one of my closing messages: Why haven't you been part of a big team science project yet?