Prenatal mother-father cortisol linkage predicts infant executive functions at 24 months

Do Parental Hormone Levels Synchronize During the Prenatal and Postpartum Periods? A Systematic Review

Physiological synchrony is the phenomenon of linked physiological processes among two or more individuals. Evidence of linkage between dyads has been found among a broad range of physiological indices, including the endocrine systems. During the transition to parenthood, both men and women undergo hormonal changes that facilitate parenting behavior. The present review sought to address the question as to whether hormonal synchronization occurs among expecting or new parents. A systematic literature search yielded 13 eligible records. The evidence of cortisol synchrony during the prenatal period, with additional testosterone, prolactin, and progesterone covariations in the time leading up to childbirth, was found to be most significant. During the postpartum period, parental synchrony was reported for oxytocin, testosterone, and cortisol levels. The implications of these covariations were found to translate into adaptive parenting behaviors and the facilitation of romantic bond. Associations with infant development were also reported, suggesting far-reaching effects of hormonal synchrony outside the parental dyad. The results highlight the importance of physiological interrelatedness during this sensitive period, underscoring the need for further research in this field. In view of the limited data available in this research domain, we have put forward a framework for future studies, recommending the adoption of standardized research protocols and repeated collections of specimens.

Universality and context-specificity in early executive function development

A renewed interest in early executive function (i.e., EF or the conscious control of thought and behavior) development has led several research groups to suggest that EF may be emerging and is less coordinated (e.g., showing few relations between tasks) in the first few years (Devine et al., 2019; Gago Galvagno et al., 2021; Johansson et al., 2016; Miller & Marcovitch, 2015; Ribner et al., 2022). This potentially universal development in EF does not exclude the possibility that EF may also differ across context (e.g., Gago Galvagno et al., 2021; Lohndorf et al., 2019; Tran et al., 2015) reflecting unique strengths and development built within one's sociocultural environment. The present paper explores potential universal and context-specific early EF developments by focusing on three aims: (1) reviewing work on EF within the first two years of life that may speak to potential universality in the measurement, structure, growth, stability, and conceptualization of early EF (2) reviewing research that may speak to how the sociocultural context may play a role in context-specific development within early EF and (3) examining potential developmental EF frameworks for understanding universal and context-specific developments of early EF within context.

Mothers' and fathers' executive function both predict emergent executive function in toddlerhood

There are multivariate influences on the development of children's executive function throughout the lifespan and substantial individual differences can be seen as early as when children are 1 and 2 years of age. These individual differences are moderately stable throughout early childhood, but more research is needed to better understand their origins. To some degree, individual differences in executive function are correlated between mother and child, but no research to date has examined these associations prior to when children are preschool age, nor have any studies considered the role of fathers' and mothers' executive function in tandem. Here, we use a sample of 484 families (Mothers 89.2% white; Fathers 92.5% white) in three countries (UK, USA, Netherlands) to investigate the role of each parents' executive function on the development of children's (49.7% female) executive function from 14 (M = 14.42, SD = 0.57) to 24 (M = 24.47, SD = 0.78) months, as well as parenting practices that underlie these associations. Results of structural equation models suggest stability in some-but not all-components of executive function and growing unity between components as children age. We replicate extant findings such that mothers' executive function predicts children's executive function over and above stability and extend these findings to include associations between father and child skills. We find an additive role of fathers' EF, similar in magnitude to the role of mothers' EF. Finally, for both mothers and fathers we find that sensitivity and autonomy supportive practices mediate the relations between parents' and children's executive function.