Healthy aging and cognitive functioning
Cognitive functioning, understood as the process and the abilities for acquiring and processing information, reasoning and decision-making, is a key component of daily functioning (Jeon et al., 2022). Cognitive decline can negatively impact an individual's ability to carry out everyday tasks, which implies a loss of independence and quality of life (Thorvaldsson et al., 2016). Lower levels of cognitive functioning are closely linked to deteriorated mental health and well-being, making it a fundamental part of healthy aging (Martinussen et al., 2019).
While normal aging is associated with a decline in cognitive functioning due to natural brain changes, social disparities in cognitive functioning cannot be explained by these biological processes alone (Bishop et al., 2010). Higher mental complexity of the main lifetime occupation is predictive of the level and trajectory of change in cognitive functioning (Finkel et al., 2009). Likewise, the cognitive enrichment theory posits that intellectual and social activities improve cognition, meaning that inactive lifestyles can accelerate decline in cognitive functioning, whereas exposure to various stimuli can prevent or delay decline in cognitive functioning (Hertzog et al., 2008). Further, there is evidence regarding substantial cognitive inequalities among diverse socio-environmental contexts for older adults (Forrester et al., 2019). Notably, sex/gender and SES are key determinants of disparities in trajectories of cognitive functioning (Walsemann et al., 2022).
Transition to grandparenthood and healthy aging
As the intergenerational overlap is being prolonged due to increasing life expectancy, research has expanded to encompass the dynamics of grandparent-grandchildren relations (Taubman – Ben-Ari et al., 2018). These relationships can be vital sources of support and social integration within families, but also of stress and additional burden in late-life (Bordone et al., 2023). At the same time, growing residential mobility could diminish the benefits of becoming a grandparent, as grandchildren may live further away (Hank et al., 2018).
The transition to grandparenthood can increase social interaction, help maintain positive emotions like sense of purpose and belonging, as well as strengthen intergenerational ties (Arpino & Bordone, 2014). On the other hand, negative self-perceptions such as feeling older, increased stress or burdens related to care provision and intergenerational re-allocation of care resources are linked to mental health decline in older adults (Bordone et al., 2023; Tanskanen et al., 2019). A growing body of literature is exploring grandparenthood and its consequences for older adults’ mental health and well-being, both regarding the event of transition to grandparenthood itself and the practices that follow in the new status, namely behavioral aspects and grandparenting (e.g., childcare). As Bordone et al. (2023) propose, it is appropriate to differentiate both aspects. Focusing on the transition, despite early calls to explore the impact of such an important life-course event (Cunningham-Burley, 1986), the scarce research that explored its effect on healthy aging mostly involved cross-sectional analyses (i.e., comparing grandparents with non-grandparents) that generated ambiguous findings. Hence, looking at the transition longitudinally is needed to better understand its consequences in healthy aging.
The few studies investigating the transition to grandparenthood with large-scale European data provide modest evidence of benefits for mental health and well-being (Bordone & Arpino, 2019; Di Gessa et al., 2020; Leimer & van Ewijk, 2022; Sheppard & Monden, 2019; Tanskanen et al., 2019). In line with cross-sectional evidence (Arpino & Bordone, 2014), these studies show effect heterogeneities based on social determinants, such as more pronounced benefits for women. While such transition is a chance to promote healthy aging for older adults (Taubman – Ben-Ari et al., 2018), evidence remains scarce and inconclusive, hence further research is needed regarding how social position influences the relation between transition to grandparenthood and cognitive functioning.
While several studies highlight the importance of social determinants for late-life cognitive functioning, most have analyzed social determinants separately rather than in combination (Cicero et al. (2023) for an exception). This leads to an incomplete understanding of the complex ways in which life-course cumulative exposures and critical events may impact cognitive functioning. Considering multiple axes of interaction between social determinants can help us address critical knowledge gaps related to cognitive functioning disparities in older adults (Hale et al., 2022). Since intersectionality has rarely been applied to explore healthy aging in quantitative studies, and as advocated by Hale et al. (2022), an intersectional approach is fundamental to understand heterogeneity in cognitive aging inequalities.
Intersectionality framework
Intersectionality theory emphasizes how multiple social characteristics intersect to create unique social positions with particular exposures to oppression and privilege (Crenshaw, 1990). Analyzing how several social determinants interact and act simultaneously to shape health outcomes is crucial to gain a more nuanced understanding of healthy aging inequalities. Likewise, it is important to understand late-life by situating it within the socially constructed nature of life-course, where privileges and resources are unequally distributed (Holman & Walker, 2021). Continuous exposure to social determinants that dynamically interact throughout the life-course generate cumulative (dis)advantages and greater disparities in late-life cognition (Crimmins, 2020). Thus, the social context is required to fully comprehend the healthy aging process, by considering both accumulation of (dis)advantages over time and through multiple intersecting social determinants. Regarding how social position relates to grandparenthood effects on cognitive functioning, neither studies on grandparental childcare (Ahn & Choi, 2019; Arpino & Bordone, 2014; Sneed & Schulz, 2019; Xu, 2022) nor the only study assessing the transition to grandparenthood (Leimer & van Ewijk, 2022) adopted an intersectional perspective.
The present study: A longitudinal, intersectional study of grandparenthood and cognitive functioning using MAIHDA
Recent literature in health disparities research advocated for a novel quantitative intersectional methodology, which materialized in the development of Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) by Clare Evans et al. (2018). MAIHDA is an analytical approach useful to understand how multiple dimensions of social inequality influence health outcomes across and within intersectional strata. Its methodological advantages relate to improved scalability, model parsimony and ability to deal with small subgroup samples (Merlo, 2018). An essential characteristic of MAIHDA is the capability to provide precision-weighted estimates for each intersectional stratum, while overcoming the problem of multiple testing by applying a shrinkage factor to obtain residuals (Bell et al., 2019). An increasing number of studies have applied this framework to investigate how the intersection of (dis)advantaged social identities affect multiple health outcomes (Axelsson Fisk et al., 2018; Bell et al., 2019; Moreno-Agostino et al., 2023). To the best of our knowledge, there has only been one MAIHDA study on biomarkers of healthy aging for older English adults (Holman et al., 2020), therefore more research on healthy aging inequalities with MAIHDA is needed.
The present study aims to shed light on intersectionality, grandparenthood and healthy aging in several ways. Building on previous work that investigated the transition to grandparenthood with data from the Survey of Health, Aging and Retirement in Europe (SHARE) and multilevel modelling (Leimer & van Ewijk, 2022; Tanskanen et al., 2019; Yang, 2021), we integrate MAIHDA with a multilevel longitudinal framework to investigate the research question: How does the influence of transition to grandparenthood on cognitive functioning vary across intersectional strata? Particularly, we aim to: (1) determine if intersecting social inequalities explain the variance in late-life cognitive functioning; (2) measure the influence becoming a grandparent on cognitive functioning; and (3) examine how the impact of transition to grandparenthood on cognitive functioning varies across intersectional strata.