Father Trials: Hormonal and Behavioral Experiments on Prenatal and Postnatal Parenting

Informations projet

FATHER TRIALS

N° de convention de subvention: 669249

DOI

10.3030/669249

Projet clôturé

Date de signature de la CE 10 Septembre 2015

Date de début 1 Janvier 2016

Date de fin 31 Decembre 2021

Financé au titre de

• EXCELLENT SCIENCE - European Research Council (ERC)

Coût total

€ 2 460 500,00

Contribution de l’UE

€ 2 460 500,00

Coordonné par

STICHTING VU
Netherlands

Periodic Reporting for period 4 - FATHER TRIALS (Father Trials: Hormonal and Behavioral Experiments on Prenatal and Postnatal Parenting )

Période du rapport: 2020-02-01 au 2021-12-31

Résumé du contexte et des objectifs généraux du projet

Fathers have largely been neglected in parenting research -- although they constitute about 50% of parents. In the current project we test the hypothesis that fathers’ parenting is affected by their hormonal levels, and can be changed by behavioural and hormonal interventions.

This project combines two types of experiments (hormonal administration and behavioural intervention), in a critical phase of parenthood: the transition to having the first baby. The focus lies on the 50% of parents who have tended to be neglected in research: fathers.
We observe fathers’ sensitive parenting behaviour, a key construct in research on parenting. It refers to the ability to attend to infant signals and to respond promptly and appropriately. Higher levels of parental sensitivity predict more favourable child outcomes, irrespective of cultural or socio-economic context. Although the quantity of time invested in parenting is generally considered less important than quality (“quality time”), it is easy to see that it takes considerable time to get to know an infant, become aware of its preferences, and read its signals. Fathers spend on average less than half as much time in direct one-on-one interaction with their children as mothers, especially in early childhood. For most young fathers, spending more time in interaction with their infant will add to the quality of the interaction. Such an increase in interaction time may also affect their hormonal levels and brain processes.

An additional focus in the current project is on a dimension of parenting that has received considerable attention in animal research but, despite its evolutionary importance, not in studies on humans: protection. Protection is a crucial aspect of human parenting. This is perhaps demonstrated most convincingly when we are confronted with the absence of parental protection, i.e. neglect, or the opposite of parental protection, i.e. child physical abuse.

In this project fathers are observed prenatally and postnatally, both with their own child and using experimentally manipulated infant stimuli and a life-like baby doll. We have tested the effects of hormonal and behavioural interventions on the neural processing of infant crying, on protective parenting, and on the quantity and quality of father-child interaction. The aim is both practical and theoretical: Testing the efficacy of the behavioural experimental interventions in boosting fathers’ participation in and quality of caregiving activities has clear practical significance (for fathers, mothers, children, and society), while examining the hormonal and neural mechanisms is crucial for the development of theory on the interplay between neuroscience and behaviour.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

Literature reviews were written on the role of oxytocin in parenting (Feldman & Bakermans-Kranenburg, 2017; Van IJzendoorn & Bakermans-Kranenburg, 2016), on fathering (Bakermans-Kranenburg et al., 2019), and on protective parenting (Bakermans-Kranenburg & Van IJzendoorn, 2017a, 2017b). We conducted two meta-analysis, one of the role of testosterone in parenting (Meijer et al., 2019), and one on the neural processing of infant cry sounds (Witteman et al., 2019). A series of papers on oxytocin experiments (Mah et al., 2016; Riem et al., 2017, 2019; Verhees et al., 2018, 2019; Witte, 2022), and exposure to infant signals (Heckendorff et al., 2016; Riem et al., 2017; 2021) were published, and invited lectures on fathering and video feedback intervention were given (2017, 2018, 2019; 2020; 2021), during the Covid-19 pandemic also online.

We demonstrated the role of oxytocin and vasopressin in neural and behavioural responses to infant crying sounds (Thijssen et al., 2018; Alyousefi-van Dijk, 2019; Witte et al., 2022), and we showed the influence of the birth of their first child on father’s protective parenting and way they talk about their babies (Van ‘t Veer et al., 2019; Lotz et al., 2021). Moreover, we showed that in new fathers more time spent on active childcare is related to stronger connectivity networks in the parental brain (Horstman et al., 2021).

Because we consider the move to open science and preregistration essential, we preregistered our hormone administration study (Witte et al., 2019), and preregistered most of our other studies on the platform of the Open Science Framework.

A Dutch website has been launched, presentations on young parents events have been given, and we have disseminated our results among midwifes and organizers of pregnancy courses and ‘daddy-classes’. We have been on the Dutch television (“Kennis van Nu”) on the BBC radio 4 (“The Science of Dad”), and an ARTE documentary of our prenatal video-feedback method is currently produced.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

Beyond the proposed or expected research findings are three key issues:
1. Concerning the role of testosterone in human parenting, we showed that the meta-analytical support for the ‘challenge hypothesis’ is equivocal (Meijer et al., 2019). The challenge hypothesis suggests that testosterone levels of adult men rise under conditions of competition and reproductivity. For competitive mating, higher levels of testosterone are favorable, but lower testosterone levels are supposed to be more conducive for caring for offspring. We did find that having a child and displaying more active paternal involvement or higher parenting quality were related to somewhat lower testosterone levels, but the combined effect sizes were small and there is evidence that publication bias might play a role.

2. We developed an empirically based neural model of infant cry perception, and for the first time, we could compare neural processing of infant cry sounds between males versus females, and parents versus non-parents (Witteman et al., 2019). We found involvement of the auditory system, the thalamocingulate circuit, the dorsal anterior insula, the pre-supplementary motor area and dorsomedial prefrontal cortex and the inferior frontal gyrus in infant cry perception, but not of the reward pathway. Structures related to motoric processing, possibly supporting the preparation of a parenting response, were also involved. Females (more than males) and parents (more than non-parents) recruited a cortico-limbic sensorimotor integration network, offering a neural explanation for previously observed enhanced processing of infant cries in these sub-groups.

3. We have demonstrated that it is possible to support father-infant interaction before birth of the infant. Using ultrasound imaging, infant responses to father’s voice or massaging hands were made visible. The videotaped interaction, including the ultrasound images of the baby, was used for feedback promoting fathers’ sensitive responsiveness. Importantly, we demonstrated in a randomized controlled trial (RCT) that two months after the birth of their baby, fathers who received the intervention showed more sensitive caregiving behaviour than fathers in the control group who received information about the growth and development of their unborn baby (Buisman et al., 2022). The interest of professionals and the general public in this prenatal video feedback programme (VIPP-PRE, Video-feedback Intervention to promote Positive Parenting – Prenatal; Alyousefi-Van Dijk et al., 2021; De Waal et al., 2022) is overwhelming. A manual for providing the VIPP-PRE intervention has been produced.

Neural Activity in Response to infant Crying

A Biobehavioral Model of Emergent Fatherhood