Three studies of young children

I don’t often use articles dealing with toddlers and preschoolers, but I found each of these articles intriguing. First, Munoz, Kartushina & Mayor (2024) published “Sustained Pacifier Use is Associated with Smaller Vocabulary Sizes at 1 and 2 Years of Age: A cross-sectional study” in Developmental Science. Here is the edited abstract:

“Pacifier use during childhood has been hypothesized to interfere with language processing, but, to date, there is limited evidence revealing detrimental effects of prolonged pacifier use on infant vocabulary learning. In the present study, parents of 12- and 24-month-old infants were recruited in Oslo (Norway). The sample included 1187 monolingual full-term born (without visual, auditory, or cognitive impairments) infants: 452 (230 girls; 222 boys) 12-month-olds and 735 (345 girls; 390 boys) 24-month-olds. Parents filled out an online Norwegian Communicative Development Inventory (CDI), which assesses the vocabulary in comprehension and production for 12-month-old infants and in production only for 24-month-old infants. CDI scores were transformed into age- and sex-adjusted percentiles using Norwegian norms. Additionally, parents retrospectively reported their child's daytime pacifier use, in hours, at 2-month intervals, from birth to the assessment date. Maternal education was used to control, in the analyses, for the socio-economic status.

We found that greater pacifier use in an infant's lifespan was associated with lower vocabulary size. Pacifier use later in life was more negatively associated with vocabulary size than precocious use, and increased the odds of being a low language scorer.

In sum, our study moves beyond the findings of momentary effects of experimentally induced “impairment” in articulators’ movement on speech perception and suggests that, from 12 months of age, constraints on the infant's speech articulators (pacifier use) may be negatively associated with word comprehension and production.”

The article, which is available open source, is quite fascinating. I like both the methodology and the findings. Pacifier use has to be introduced by parents, usually mothers. The next two studies look further at parental behavior. Ogren, LoBue & Sandhofer (2024) published “How Do Emotion Words Impact Children’s Emotion Learning?” in Developmental Psychology.  Here are the edited abstract  and impact statements:

“Previous research suggests that the use of emotion labels helps children to learn about emotions. However, the mechanism behind this relation remains somewhat elusive. The present study examined 3-year-old children’s (N = 72; Mage = 3.51 years; 42 female) ability to match faces to emotional vignettes, and the role that the use of emotion labels plays in this process. Parents identified participating children as White (N = 37), multiracial (N = 17), African American/Black (N = 5), Asian (N = 5), Hispanic (N = 3), Latino (N = 2), South Asian/Indian (N = 1), Middle Eastern (N = 1), and other (N = 1), and most children had a parent with a college degree (N = 66). After a pretest, children heard either explicit emotion labels (“she feels annoyed”), novel labels (“she feels wuggy”), or irrelevant information (“she sits down”) paired with a vignette and associated facial configuration. Children were then tested again at posttest for evidence of learning. Results revealed that children only improved from pre- to posttest in the explicit label condition, demonstrating that explicit emotion labels, which are likely to be familiar to children, facilitate children’s learning of emotion information. Altogether, our results suggest that familiarity with emotion words from prior daily experience may best explain how emotion words influence children’s learning about emotions.

Hearing emotion words helps young children to learn about emotion categories. However, we do not yet know exactly how. This study finds that children learn best from emotion words that they have likely heard before over a period of years, suggesting that there is a benefit to hearing the same emotion words many times throughout their daily experiences.”

I love the methodology used here and the findings make perfect sense. The next study also looks at preschoolers. Li, Degirmencioglu & Lunkenheimer (2024) published “Observed Child Behavioral Self-Regulation and Maternal Supportive Parenting are Associated with Dynamic Physiological Stress Reactivity in Preschoolers” in Developmental Psychology. The abstract and impact statements follow:

“This study sought to advance our understanding of how observed child self-regulation, parenting, and their interaction were associated with children’s dynamic physiological stress reactivity indexed by respiratory sinus arrhythmia (RSA) reactivity trajectories. Participants were 85 three-year-old children (54% female) and their mothers oversampled for lower income, higher stressful life events, and higher child maltreatment risk. Child behavioral regulation, assessed as compliance and noncompliance, and maternal supportive parenting were observed during a challenging dyadic puzzle task. Results showed that child RSA exhibited quadratic change across the task on average, characterized by an expected initial decrease and subsequent recovery. Child behavioral regulation and its interaction with maternal supportive parenting were associated with interindividual differences in child RSA reactivity trajectories after controlling for child resting RSA. Children with higher compliance or lower noncompliance showed RSA decreases in response to task stressors but exhibited subsequent RSA recovery only when mothers displayed higher supportive parenting. Children with lower compliance or higher noncompliance displayed negligible RSA changes overall across the task, suggesting blunted or compromised RSA reactivity, regardless of supportive parenting levels. These findings demonstrate novel evidence that preschoolers’ better behavioral regulation is related to their more adaptive physiological reactivity to stressors and that supportive parenting is needed to facilitate physiological recovery even in relatively better-regulated preschoolers. 

This study demonstrates that during challenging mother–preschooler interactions, preschoolers who exhibit better behavioral regulation with mothers and experience higher levels of supportive parenting show the most adaptive physiological reactivity to stressors and efficient physiological recovery after stressors have passed. Child self-regulation and parenting in challenging interactions are potential intervention targets to promote adaptive physiology and behaviors.”

I’ve written once before about maternal behavior and RSA with Li and Lunkenheimer as authors of one of those studies. While their previous study looked at harsh parenting, this one looks at the flip side of supportive parenting. Taken together, all three of these studies provide important evidence of harmful and beneficial parenting choices.