In the contemporary nuclear family, fewer children are born, both parents work, and it is rare for other relatives (such as parents, siblings, uncles, or other elderly family members) to live in the household. Both partners share the responsibilities of raising and caring for their children. When a child is born, today’s parents often find themselves alone. As both parents work, raising a newborn becomes more challenging, necessitating support from other adults. The absence of a network of women who, in patriarchal societies, could provide assistance (such as sisters, aunts, and cousins) makes it necessary to seek help elsewhere. In families where grandparents are available, they constitute a crucial resource and become indispensable, at least during the early years. As caregivers, they take care of newborns by feeding, bathing, changing diapers, rocking, dressing, holding, putting them to sleep, escorting them to and from daycare or school, educating, telling stories, talking and playing with their grandchildren, and protecting them both inside and outside the home. While for many individuals becoming grandparents is one of the most fulfilling experiences in life, making them feel younger and more energetic, for others, it represents a challenging existential transition. Some refuse to embrace grandparenthood as it is perceived as a narcissistic wound, symbolizing aging, a loss of power, and the approach of death.
It is well established that fathers (or partners, including same-sex partners) who assume caregiving responsibilities for a newborn exhibit significant neuroendocrine and epigenetic changes. These changes also occur in grandparents when they undertake caregiving roles for an infant. To date, as far as we know, research has only focused on grandmothers, with no studies conducted on grandfathers. Research in mothers, fathers, and grandmothers has led to the hypothesis of a Global Parenting Caregiving System in our species, which is activated even in nonmaternal caregivers (allomothers) and involves at least ten brain regions along with endocrine and epigenetic modifications