Going beyond description - A fourfold methodological approach to analyze the effects of caregivers on infant smiling behavior and development

DFG funded project (KA 3451/9-1) in cooperation with Prof. Dr. Iris Nomikou (University of Portsmouth), Prof. Dr. Daniel Messinger (University of Miami), Jorge Mantilla (Universidad de Otavalo) & Marc de Lussanet de la Sablonière (University of Münster)

Funding period: 2024 bis 2026

Contact: Joscha Kärtner

Based on a completed data assessment of mothers and infants from two cultures that were shown to differ concerning maternal ethnotheories about ideal infant affect, namely mothers from urban middle-class families from Münster and mothers from rural Kichwa families in Ecuador, the proposed project aims at providing converging evidence for the effects of caregivers on infant smiling behavior and development across different methodological approaches. The data include standardized assessments of caregivers’ ethnotheories in postnatal week 7, longitudinal observations of naturalistic mother-infant interaction from week 8 to 18 and infant gaze and smile during standardized experimenter-infant interaction with varying levels of stimulation in weeks 12 and 18. The longitudinal observational approach allows to analyze the developmental trajectories of infant smiling and maternal behavior across weeks 8 to 18. The cross-cultural approach allows to, first, contrast caregivers’ ethnotheories about infant smiling and their manifestation in caregivers’ behavior during mother-infant interaction and, second, to analyze the emergence of potentially culture-specific developmental pathways of infant smiling between 2 and 5 months of age. The standardized approach allows, first, to substantiate the assumption that caregivers’ culture-specific ethnotheories are the driving force of the expected cross-cultural differences in smiling behavior and development, namely by showing that they explain a significant proportion of the cross-cultural differences found. Second, the assessment of infants’ responsiveness to standardized smiling stimulation allows to assess implications of maternal behavior for generalized infant development, namely outside of the mother-infant dyad and across developmental time. Finally, the process approach allows to analyze the dynamics of mother-infant interaction associated with infant smiling, with a specific focus on the bidirectional coupling of infant smiling and maternal smiling and stimulation and how these links change across developmental time. While the analyses described above are based on multilevel mixed linear models, the process analyses are based on specific time-series analyses, namely multilevel bivariate autoregressive (AR) models and multilevel threshold bivariate autoregressive (TAR) models. In all analyses, we follow the main hypothesis that mother and infant behavior around infant smiling, that is, maternal stimulation of affect-expressive behavior and maternal and infant affect-expressive behavior in different modalities, is more pronounced in the Münster dyads as compared to the Kichwa dyads. Furthermore, we will test whether the hypothesized cross-cultural differences can be explained by differences in caregivers’ ethnotheories about ideal infant affect. Overall, these analyses have the potential to provide converging evidence for the effects of caregivers on infant smiling behavior and development.

Selected publications:

Kärtner, J., Schwick, M.*, Wefers, H & Nomikou, I. (2022). Interactional preludes to infants’ affective climax. Infant Behavior and Development, 67, 101715. https://doi.org/10.1016/j.infbeh.2022.101715                                                                                       * shared first author

Wefers, H., Schuhmacher, N., Hernández Chacón, L. & Kärtner, J. (2023). Universality without the uniformity – Infants’ reactions to unresponsive partners in urban Germany and rural Ecuador. Memory & Cognition, 51, 807–823. https://doi.org/10.3758/s13421-022-01318-x

Wefers, H., Schwarz, C. L., Hernández Chacón, L., & Kärtner, J. (2022). Maternal ethnotheories about infants’ ideal states in two cultures. Journal of Cross-Cultural Psychology, 53(6), 603–625. https://doi.org/10.1177/00220221221096785