TY - JOUR
T1 - Quantifying sources of variability in infancy research using the infant-directed speech preference
AU - The ManyBabies Consortium
AU - Ota, Mitsuhiko
AU - Rabagliati, Hugh
AU - Skarabela, Barbora
PY - 2020/3/16
Y1 - 2020/3/16
N2 - The field of psychology has become increasingly concerned with issues related to methodology and replicability. Infancy researchers face specific challenges related to replicability: high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations, amongst other factors. Addressing these concerns, we report on a large-scale, multi-site study aimed at 1) assessing the overall replicability of a single theoretically-important phenomenon and 2) examining methodological, situational, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult were created using semi-naturalistic laboratory-based audio recordings in North American English. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three commonly-used infant discrimination methods (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s *d*) was 0.35 [0.29 - 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together these findings replicate the infant-directed speech preference but suggest that its magnitude is modulated by development, native language experience, and testing procedure.
AB - The field of psychology has become increasingly concerned with issues related to methodology and replicability. Infancy researchers face specific challenges related to replicability: high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations, amongst other factors. Addressing these concerns, we report on a large-scale, multi-site study aimed at 1) assessing the overall replicability of a single theoretically-important phenomenon and 2) examining methodological, situational, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult were created using semi-naturalistic laboratory-based audio recordings in North American English. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three commonly-used infant discrimination methods (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s *d*) was 0.35 [0.29 - 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together these findings replicate the infant-directed speech preference but suggest that its magnitude is modulated by development, native language experience, and testing procedure.
KW - language acquisition
KW - speech perception
KW - infant-directed speech
KW - reproducibility
KW - experimental methods
KW - open data
KW - open materials
KW - preregistered
U2 - 10.1177/2515245919900809
DO - 10.1177/2515245919900809
M3 - Article
JO - Advances in Methods and Practices in Psychological Science
JF - Advances in Methods and Practices in Psychological Science
SN - 2515-2459
ER -