Rebecca Pearson ^1* Bronwyne Coetzee ² Tamsen Jean Rochat ¹

• ¹ Manchester Metropolitan University, Manchester, United Kingdom
• ² University of the Witwatersrand, Johannesburg, South Africa

Most papers focused on infancy or early childhood and on interactions with mothers (12 out of 14), which reflects an imbalance in the broader understanding of the value of interaction and relationships across childhood and into adolescents and adulthood. This limits our understanding of the complex tapestry of relationship dynamics that emerge as children grow, in particular as their relational capacities develop with and through interactions with multiple family members including fathers (which only two papers focused on) and siblings. Children develop their capacities to contribute to interactions as they grow through developmental transitions aimed at developing their independence and autonomy. The current focus on the early years leaves several gaps in our understanding of how interaction develops alongside other socioemotional and cognitive capacities, and how interactions shift and shape beyond the motherchild dyad. This limits the potential to innovate in how we intervene at different developmental stages and contexts. It also introduces methodological vulnerabilities because the existing methodologies used for infancy research do not necessarily translate to older age groups. For example, concepts robust in infancy are taken as the gold standard, but we should not assume that concepts such as sensitivity and attachment present in the same way or have the same role in adolescence, a time at which successful developmental transitions would require greater autonomy meaning that it may be adaptive to have 'de-attach'. Studies included in the collections offered considerations of this and present potential methodological approaches which could inform observational research in middle childhood and adolescence. (Wright et al., Deshani et al.,).Much like looking forward to later development is important, considering pre-conception (including previous intergenerational pathways) and the prenatal period is key. While the prenatal period is recognized biologically as having an impact on fetal and thus child development, its psycho-social influence on parent-child interactions is often overlooked. One study looked at the role of BMI in pre-pregnancy on later peer problems, recognizing both biological and social pathways. No papers came forward looking at multi-generational influences.Parents are always parents, and their role and influence likely extend beyond the dependent years even into many generations after their death. Similarly, modern and complex ways of experiencing and contrasting the context of parent-child relationships were not extensively explored in this collection, including that no studies captured the complexities half, step adoptive, single parents, same-sex parenthood. We specified that we were interested in interactions, and this was considered by authors in many ways. Some studies examined interactions in their simplest forms; exploring well known construct's like 'responsiveness' while others explored developing more complex coding matrix's on mutual affect and what can be learn from micro-coding, emotional recognition and the use of Artificial Intelligence (AI) and how these technologies may support an openness to new understandings not limited by historical knowledge and standards. In addition, more global assessments of interactions were included such as concepts of sensitivity or attachment, these are taken not from one moment alone. Rather, concepts such as sensitivity are taken as greater than the component micro moments and in someways rely on a subjective sense by the observer. Greater periods of time were generally assessed by self-report of perceptions, these included simple proxies of interactions based on working hours in Japan or use of routines during lockdown or recall of childhood events such as neglect or emotional trauma in parentchild relationships.The collection does suggest researchers are beginning to grapple with this and expand methodologies to include bio-psycho-social processes as a means to engage with the potential multiple and competing pathways that may be involved in outcomes, see for example Braithwaite examination of interactions and their biological signals embedded in DNA methylation. These different ways of 'knowing' or gaining insights into the parent-child interaction or relationship were exciting to see and next steps may include triangulation and understanding.Other exciting methodological developments include the richness of new tasks and protocols presented as part of the collection. These explored creative approaches in protocol development to observe parent-child interactions; free play, structure, attachment protocols, specific games, in research 'labs' or at home. These extend to the use of new technology such as wearable cams, and AI which offer exciting opportunities for future research. Similarly a refreshing theme of co-production and creativity in engagement emerged from the papers as a new norm and foundation to challenge ideas and develop methodology. Such co-production included art (Culpin et al.,), mobile pop-up events (Wright et al.,) and new ways of engaging in 'talk' with adolescents in groups (Deshani et al.,).In addition, to gain statistical power to reach larger sample size, it is key that more work is done in collaboration and that data sharing and harmonization is a priority. Some important examples are found in this collection, with studies designing aligned protocols in multiple settings (Bornstein et al.,), or protocols being developed to harmonize data from consortiums of cohort studies that followed different protocols and did not initially aim to be brought together (Dream Big-Consortium) Only one study investigated the role of interventions (Braithewaite et al.,). However, many more provided evidence for potential.For example, the use of wearable cameras to enhance video-feedback via first person perspective, noted in 3 of the included papers in this topic. This is important as, a recent metaanalysis of 59 randomised controlled studies found that psycho-educational advice alone is not effective in reducing later mental health disorders. Rather, relational support at home, in practice is the key causal ingredient in parenting interventions in preventing mental health risk and increasing parents' self-efficacy.Wearable camera devices with both the child and baby as described in this topic (Skinner et al.), capturing the same moment for both parties, enables viewing of shared emotion, how the interaction was different from different viewpoints, aiding introspection and reflective functioning. Co-production development work highlighted in this topic (Wright et al.,), reports that parents notice more mental state signals when viewing first person perspective footage and parents can more easily re-live the moment when it is viewed back 'through their eyes In addition, some of the AI discussed in this issue such as face-reader could support interventions. Finding moments of strength is key to video-feedback but is limited by practitioners scanning through lots of footage, hampered by natural human subjectivity/error. Face-reader technology, described in this topic, records intensity of emotions (such as sadness, happiness) concurrently in parent and child on a scale between 0 and 1, every 0.02 seconds, allowing statistical modelling of subtle transitions in emotion. Face-reader processing systems, could automatically indicate key moments, drastically saving time and potentially standardizing selection of footage alongside personalized input, where AI and therapists work together. Finally, studies in this collection looked at the role of previous contexts on later outcomes (Hill et al.,) demonstrating that when trauma happens (in this case exposure to violence) the child's attachment history is relevant, much like trauma informed care and how they may interact with mindfulness in predicting later eating disorders (Royer et al.,). In combination, this supports more personalized and systemic approaches to parenting interventions considering a developmental lense.