**4. Intergenerationality and childlessness**

Childlessness hinders the normative vertical intergenerationally. Little is known about the population without intergenerational bonds [40], despite being a fastgrowing population segment because it is an emerging research issue in contemporary societies [41]. This situation can be voluntary (childfree) or involuntary (childless), either lifetime childlessness or permanent or definitive childlessness [5, 41], but with similar repercussions in terms of intergenerationally in advanced ages.

The demographic and social trends observed in families, gender, and aging patterns combine into a demographic transition that produces diversification in models, structures, and roles in intergenerational relations [42]. The shrinking size of families, the fall of fertility and birth rate, and the number of children, as well as the changes in marriage and the family formation, the increase in divorces or union dissolution, the increase of single-parent families or in the elderly living alone and the life expectancy at birth increasing, are some examples that are reported as macro-level factors (e.g., [41]).

Childlessness among both men and women has increased throughout the European countries at ages 30–34 and 40–44 years old, mostly involuntary [41]. The same increase happens in the age group 40–44 in most OECD countries [5]. Childlessness in Europe is positively associated with a higher mean age at marriage and with more delayed motherhood. On the other hand, childlessness is negatively associated with ever married proportions and with fertility rates. European men with little education and women with either very high or very low education are

more common childless people. Higher childlessness rates are found in widespread individualist values countries [41].

The rapidly increasing proportions of childless people pose diverse challenges because of its potential impact on wellbeing, when involuntary, and "in the long run, the growing proportions of childless persons will also bring extra challenges for future aging generations through the older people who will have no adult children or grandchildren to assist and take care of them" ([41], p. 42).

Even when there is offspring, the contemporary demographic context leads to a potentially greater number of people to care for in advanced ages and a smaller number of potential family caregivers [43].

This is enhanced by the verticalization of family relations, thanks to the decrease in children's number, originating the so-called "beanpole-family", with fewer elements in each generation and less or inexistent lateral branches [44]. In familistic cultures, kinship ties are especially valued, alongside the spouse bond, emphasizing adult children's role in informal social support and care for their older parents (e.g., [45–48]).

Life trajectories with or without parenthood are associated with normative and non-normative social expectations and are necessarily different [49], shaping the meaning and the experience of childlessness [46], as well as sociability and social participation patterns [49]. Those who are childless or childfree have potentially fewer family responsibilities, more free time, and greater flexibility for extra-family and social engagement lifelong [50]. Parenthood and motherhood imply other socialization contexts not explored when there are no children, namely with other parents and childcare and education services.

Life courses and intimate relational history help understand individuals' trajectories with and without children [51, 52]. Older persons' lives result from very heterogeneous choices and features, varying according to gender, civil status, financial status, education, as well as the prior relationship with close family ties and extrafamilial ties, or either family circumstances [52–55].

The approaches appear to be divided between those who point to childlessness as an advantage or a disadvantage. However, this polarization can be reductionist to address complex and diverse relational paths [55].

However, in advanced ages, childless people tend to be perceived as disadvantaged, particularly due to the inexistence of adult children as a potential source of informal support and care [50, 54, 56, 57]. In this regard, childlessness in adulthood is pointed to as a future support deficit [58].

The childless seniors' social networks tend to be smaller compared to those who have adult children [49, 50, 59]. Other relevant demographic and social variables are associated with better or worse conditions in the social networks in old age, such as age, marital status, income, education, living alone or not, being in disadvantage those who are oldest, unmarried, and who live alone [60].

The perceived independence is valued as an advantage by childless seniors since the expectations of not having children are adapted to the situation in advanced ages [54]. Their community participation tends to be potentially more active than parents, either in religious activities [54] or volunteering [58].

There are some specificities in childless people's social networks in old age. Studies highlight the extended family, friends, and neighbors as social support sources [61], especially in an emergency or in short term care [54]. When autonomy shifts to dependence, the support needs become more demanding and continuing in the long term. To deal with the dependency, community services become a relevant source of social and healthcare support, particularly for those who live alone [54, 61]. Facing health deterioration, the childless elderly are more likely to be supported by extrafamilial relations or social services [58], which is the preferred

source of supporting the extrafamilial relationships (friends and neighbors) [62]. Different models of social support are defined for old age, integrating informal and formal systems. Children are generally identified as the preferential support system, then the absence of offspring tends to create a compensatory hierarchical model [62]. Thus, the compensation for childlessness can be done through other ties, following a preference hierarchy: first, the significant others (other relatives, friends and neighbors) and then formal social services [62] although, the availability of social support seems to be more determinant than preference in this process [63]. Nevertheless, the idea of compensating support bonds underlies a normative and conventional family perspective, not corresponding to contemporary family changes and diversity [45].

The family-centered networks and the diverse networks tend to mirror the condition facing parenthood, as we observed earlier in the present chapter. Non-kin relationships assume special importance in the childless elders' networks, being distinguished by the role of friends and neighbors [62]. The extended family is also referred to, particularly the role of brotherhood in the case of single childless persons [64] and the role of the nephews, especially when there are no siblings capable of acting as a support system [54, 57].

Psychological wellbeing of childless older persons has been addressed through a perspective that underlines the pernicious impacts of the lack of offspring and another perspective that emphasizes the lack of differences in wellbeing between those with and without children. On the one hand, there is no clear association between childlessness or parenthood and wellbeing [46, 56, 65]. Loneliness, depression, and childlessness interactions in advanced ages are addressed as having significant associations [66], but either for the lack of association between these dimensions [65], which indicates the need for further studies. Despite these disparities, there is evidence of weaker social support among the childless [56], which can be attributed to the negative impacts of lack of offspring on wellbeing throughout life trajectories.

Childless older persons are commonly associated with restricted social network types such as *nonfamily-restricted networks* [23], *small extended-family and friend-focused networks* [29], d*efective networks* [16], or *non-kin restricted networks* [21]. These networks are reported as being more vulnerable to social isolation and loneliness [16, 21] and associated with negative perceived health, dependency, and depression [23], which should bring particular attention to childlessness in adulthood old age trajectories.
