Background: Emotion regulation (ER) is shaped through interactions with caregivers, particularly parents. During infancy, emotions are co-regulated by caregivers in daily interactions, which help infants recognize internal states and progressively internalize emotion regulation strategies. Physiological indicators such as Heart Rate Variability (HRV) are widely used to study ER in preverbal infants. However, most research on infant HRV has focused on stress-inducing situations like the Still Face Paradigm, primarily involving mothers. This study aimed to examine infant ER during natural interactions with mothers, fathers, and both parents together, as well as the transitions between these relational contexts. A secondary objective was to explore the relationship between physiological ER and infant temperament.

Method: The study included 84 families with 4-month-old infants. Infant heart activity was recorded via ECG across a five-part sequence: baseline (no interaction), mother–infant play, father–infant play, mother–father–infant play, and mother–father discussion in the infant’s presence. The order of parts 2 and 3 was counterbalanced to control the effect of which parent played first. Root Mean Square of Successive Differences (RMSSD) from ECG signals was used to index HRV, and infant temperament was assessed using the Infant Behavior Questionnaire Revised – Very Short Form.

Results: Growth curve modeling showed a quadratic trajectory for RMSSD, with significant increases from part 1 to 3 and decreases from part 3 to 5. These patterns were more pronounced when mothers initiated play. Positive affectivity and orienting temperament traits were linked to greater increases and decreases in HRV, whereas negative affectivity was associated with higher baseline HRV and lower increases. Fear and affiliation traits showed no significant associations with HRV changes.

Discussion: Findings contribute to understanding how infant ER varies across relational contexts and is influenced by temperament, extending current knowledge on the interplay between ER, early social environments, and temperament.

Curiosity, as the intrinsic drive to seek knowledge engaging individuals in exploratory behaviors, is essential for learning and lifelong adaptability. Parenting is thought to enhance curiosity from the earliest stages of life. However, there is still a lack of longitudinal research investigating how parental behaviors contribute to the development of curiosity at early ages.

This longitudinal study aims to explore the role of maternal mindfulness (i.e., the ability to connect with oneself and the external world), along with maternal parenting stress, and parenting behaviors during infancy in promoting curiosity in toddlerhood.

Seventy mothers and their infants (53% male; 100% Italian; 75% first born) were observed during face-to-face interactions at 9 months old. Both maternal and infant affective behaviors were coded using the Infant and Caregiver Engagement Phase (Weinberg et al., 1989). Mothers also reported on their mindfulness and parenting stress. At 2.5 years of children’s age mothers reported on their child’s curiosity.

Results from several regression models showed that mothers with higher mindfulness during infancy had toddlers with higher scores across all curiosity domains, whereas mothers who perceived mother-child interactions as more stressful had toddlers with lower curiosity.

Mothers who spent more time looking at their infants with neutral expressions, not vocalizing—especially when the infant was exploring the environment—reported lower infant curiosity in toddlerhood. Conversely, the time spent by the mother displaying positive affect while the infant was looking at her predicted higher curiosity during toddlerhood.

These findings underscore the fundamental role of responsive and stimulating parenting in nurturing children's curiosity and engagement with the world, highlighting the potential impact of supportive parenting practices in promoting curiosity during early childhood. Implications for interventions and future research are discussed.

The integration of smart technologies into our daily lives has become pervasive. While these devices offer numerous benefits, the frequent interruption of social interactions by technology use (technoference) has been demonstrated to have adverse developmental effects on children. Given the pivotal role of environmental factors in early development, it is especially important to study technoference in mother-infant interactions. We present results from two consecutive studies investigating the effects of maternal smartphone use on interaction dynamics in different scenarios.

In our first study, we observed the behaviour of 12 mother-infant pairs during free-play to explore the patterns and effects of maternal smartphone use. Microanalysis of video recordings revealed a decline in interactivity and maternal responsiveness to infant attention-seeking behaviours. However, mothers showed different strategies for maintaining interaction by sharing attention in different modalities, and by dividing the time spent on the phone into intervals. Based on the latter, two predominant strategies were distinguished: prolonged immersion followed by a complete refocus of attention on the infant, and alternating attention between the smartphone and the infant.

In our second study, we investigated the effects of these two strategies on interaction dynamics in a modified still face situation, utilizing a repeated measures design in a face-to-face interaction setting. We examined the behaviour and affectivity of 14 mother-infant pairs. Infants aged 6-7 months exhibited signs of distress in both situations. However, microanalysis at 0.5 second intervals suggested that shorter, repeated periods of maternal smartphone use were more distressing for infants than a single but long interruption. These findings imply that the continuous reorganization of interaction poses a greater challenge to parent-infant pairs, which they find more difficult to cope with. Furthermore, the successful recovery of interaction following smartphone use was positively associated with the degree of mother-infant synchrony established during uninterrupted interactions.

Mother-infant synchrony supports early co-regulation and engagement, forming a foundation for later development such as self-regulation, language and communication, and prosocial behaviors. Despite its significance, most studies take a cross-sectional approach, offering limited insight into how synchrony unfolds over time in early childhood. This study examines developmental course of synchrony with 28 full-term, healthy infants (60.7% girls; birth weight > 2,500 g) and their mothers (Mage=32.8). We observed synchrony across five time points (8, 10, 12, 14, and 18 months) in a 5-min free-play (FP) context, where dyads interacted with a standardized set of toys. Synchrony was defined as the simultaneous exhibition of the same state in behavioral and affective domains. Behavioral synchrony was categorized into object synchrony (both partners attending to the same object) and social synchrony (partners attending to each other). Affective synchrony included positive or negative affect. We coded every second of a three-minute segment separately for behavioral and affective synchrony and calculated proportional scores. Results showed that affective synchrony was infrequent: Positive affect synchrony occurred in less than 3% of interactions, while negative affect synchrony was extremely rare. In contrast, behavioral synchrony was predominantly object-focused, averaging 56.7% of interactions and increasing from 52.6% at 8 months to 61.7% at 18 months. Social synchrony was low (2.97% on average) and fluctuated across time points. Linear mixed-effects models examined developmental changes in object and social synchrony. Object synchrony significantly increased over time, F(4, 88.2)=3.14, p=.018, with higher levels at 14 months and 18 months compared to 8 months. Social synchrony showed no clear developmental trend. These findings suggest a robust pattern of increasing object-focused synchrony in the FP context but a less consistent trajectory for social synchrony, likely influenced by contextual factors. Implications for the role of play context in shaping synchrony will be discussed.

Although previous research has shown that having children can improve the overall well-being in couples, it may also negatively impact their relationship satisfaction. Sleep problems, particularly those experienced by children and mothers, may be potential factors influencing parents relationship dynamics. The present cross-sectional study aimed to examine the mediating role of maternal sleep quality in the relationship between child's sleep quality and maternal relationship satisfaction. The study sample consisted of 345 mothers (M_age = 34.61, SD = 4.41) who are over the age of 18 and have at least one child between the ages of 1 and 5. Participants completed measures assessing demographic information, their children’s sleep quality, their own sleep quality, their relationship satisfaction, and their symptoms of depression, anxiety, and stress. Where mothers had more than one child, the data for the child with the lowest sleep quality was used. The results indicated that there was no significant direct effect of child’s sleep quality on maternal relationship satisfaction, revealing a full mediation with significant indirect (β = -.09, p < .05) and total effects (β = -.17, p < .01). This finding suggests that lower sleep quality of child predicted lower maternal relationship satisfaction through lower maternal sleep quality. After controlling for variables correlated with maternal relationship satisfaction such as age, work status, smoking, screen time at bedtime, depression, anxiety, and stress, full mediation remained with significant indirect effect (β = -.02, p < .05). The present findings highlight the importance of addressing maternal sleep quality as a potential intervention target for enhancing maternal relationship satisfaction. Strategies such as improving maternal sleep hygiene, screening for sleep disorders, and implementing parenting education programmes may help mitigate the negative effects of children’s sleep quality on maternal relationship satisfaction.