Up until a few decades ago, grandparenting was no salient topic in the sciences of human behavior. As Coall & Hertwig (C&H) have shown, it has become a topic of study on which researchers have weighed in from their respective disciplines. Grandparenting is now studied by sociologists, biologists, anthropologists, and evolutionary psychologists. The academic disciples differ in their contributions. Sociologists tend to interpret data a-theoretically. Their resistance to biological accounts of human behavior, however, frequently prevents a cut of nature at its joints: the distinctions between grandparent sexes, or lineage (parent sexes), or both, are frequently omitted in social science research (e.g., Patrick & Goedereis Reference Patrick, Goedereis and Shifren2009). Both variables, however, are pervasively important. Anthropologists, inspired by the Grandmother Hypothesis, inspect hard reproductive data such as number of offspring or grandchild mortality. Psychologists usually present soft data, such as rated emotional closeness or grandparental solicitude. C&H have done a commendable job in bringing the various approaches together and highlighting their respective contributions fairly. Their review is, in my opinion, one of the very best about grandparenting.
I take the liberty to comment on the results from Tinsley and Parke (1987). C&H interpret these results as suggestive of the beneficial effects of grandparenting on the mental development of grandchildren. C&H prudently say that the data suggest an association which is not necessarily causal. A genetic confound might be excluded by the observation that more significant associations (namely, 7) between grandparent–infant interaction patterns and infant development scores were found for grandmother–infant dyads than for grandfather–infant dyads (namely, 2). But the study does not indicate the extent to which these associations are grandparent-driven, as C&H assume, or grandchild-driven.
More important, however, is a finding by Tinsley and Parke (1987) which I consider highly relevant for the question of whether grandparenting does any good in modern Western countries. Cui bono? Grandparental care might not only be good for grandchildren (and parents, for that matter), but also for the grandparents themselves, provided the required grandparental involvement does not exceed the grandparental resources. C&H acknowledge the possible benefits of grandparenting for grandparents at the end of the target article, but they might have overlooked a noteworthy finding by Tinsley and Parke: namely, that contact with the infant was rated substantially and significantly more satisfactory by grandparents than by parents, this finding applying equally to both genders of grandparent/parent. From an evolutionary perspective, this point is to be underlined. Nepotistic effort is the salient life effort during the sunset years (Alexander Reference Alexander1987), and it therefore comes as no surprise that its practice is perceived as highly satisfying.
An impression left by the studies reviewed by C&H is that the effects of grandparental care-giving count if they have an impact on the achievement scores of grandchildren. The value of grandparenting ought not to be so narrowly defined. In addition to achievement, there is also well-being, a feeling of connectedness, happiness, and life quality, for both the grandchild and the grandparent. Objective measures (e.g., survival rates, achievement scores) as well as subjective measures need to be considered for grandparents, parents, and grandchildren.
C&H clearly describe the consequences of the demographic transition for grandparent–grandchild relationships. The shared lifespan between grandparents and grandchildren is bound to become shorter; and increasingly there is only one grandchild. We might ask whether deprivation of contact with grandchildren might have adverse effects on the life quality of the aged. I have had grandparents in my office weeping bitterly of their biggest misfortune: that they were denied contact with their only grandchild. Legislators have become sensitive towards this problem. The recognition of grandparents' visitation and custody rights is a fairly recent trend.
Also rather recent is the increased consideration of grandparents in public child welfare (Herring Reference Herring2008). Kin are increasingly used as foster parents. In the United States, the most common placement for foster care is with grandparents, usually the maternal grandmother (Scannapiego & Hegar Reference Scannapiego and Hegar2002). Legislators and welfare agencies prefer to listen to the expert advice of social scientists rather than evolutionary biologists, but the blatant disregard for biological variables may come with costs. There are asymmetries between the sexes which do not disappear by “deconstruction” or by benign neglect. If, for example, sociological studies investigate step-parent households – defined as those with either a stepmother or a stepfather – an important distinction is overlooked, namely, whether the biological parent with whom the child co-resides is the mother or the father. Mother absence is more disadvantageous to the child's development than father absence, both with respect to the investments made in children and with respect to child outcomes (Case et al. Reference Case, Lin and McLanahan2001), and parental investments are lower in stepmother families than in birth mother families (Case & Paxson Reference Case and Paxson2001). Most telling and directly relevant for grandparental care-giving are the findings by Duflo (Reference Duflo2003), who examined the flow of pensions given in South Africa to grandparents living with their grandchildren. Disturbingly, only the pensions to maternal grandmothers were channeled on to grandchildren.
The review by C&H shows that grandparental investment protects children from adverse effects in certain family situations with high risks. Risky situations may, at first glance, appear to be a matter of past epochs of famines, epidemics, and recurrent wars, or seem rare cases with little importance for normal modern families. But the list of risks, which is not exhaustive, includes maternal depression, teenage pregnancy, lone-parent, and step-parent families. These risks have such a high prevalence in modern societies that there is, and always will be, a need for helping grandparents whose assistance is good for the grandchildren – and also good for the grandparents, as long as they are not the sole caretakers. Life has been risky in the past and will remain risky in the future, even if the types of risks change with time. Therefore, contemporary grandparental care is not an evolutionary mismatch, an adaptation advantageous in ancestral environments but useless in modern times, like the hedgehog's instinct to roll itself inwards when a car approaches.
Up until a few decades ago, grandparenting was no salient topic in the sciences of human behavior. As Coall & Hertwig (C&H) have shown, it has become a topic of study on which researchers have weighed in from their respective disciplines. Grandparenting is now studied by sociologists, biologists, anthropologists, and evolutionary psychologists. The academic disciples differ in their contributions. Sociologists tend to interpret data a-theoretically. Their resistance to biological accounts of human behavior, however, frequently prevents a cut of nature at its joints: the distinctions between grandparent sexes, or lineage (parent sexes), or both, are frequently omitted in social science research (e.g., Patrick & Goedereis Reference Patrick, Goedereis and Shifren2009). Both variables, however, are pervasively important. Anthropologists, inspired by the Grandmother Hypothesis, inspect hard reproductive data such as number of offspring or grandchild mortality. Psychologists usually present soft data, such as rated emotional closeness or grandparental solicitude. C&H have done a commendable job in bringing the various approaches together and highlighting their respective contributions fairly. Their review is, in my opinion, one of the very best about grandparenting.
I take the liberty to comment on the results from Tinsley and Parke (1987). C&H interpret these results as suggestive of the beneficial effects of grandparenting on the mental development of grandchildren. C&H prudently say that the data suggest an association which is not necessarily causal. A genetic confound might be excluded by the observation that more significant associations (namely, 7) between grandparent–infant interaction patterns and infant development scores were found for grandmother–infant dyads than for grandfather–infant dyads (namely, 2). But the study does not indicate the extent to which these associations are grandparent-driven, as C&H assume, or grandchild-driven.
More important, however, is a finding by Tinsley and Parke (1987) which I consider highly relevant for the question of whether grandparenting does any good in modern Western countries. Cui bono? Grandparental care might not only be good for grandchildren (and parents, for that matter), but also for the grandparents themselves, provided the required grandparental involvement does not exceed the grandparental resources. C&H acknowledge the possible benefits of grandparenting for grandparents at the end of the target article, but they might have overlooked a noteworthy finding by Tinsley and Parke: namely, that contact with the infant was rated substantially and significantly more satisfactory by grandparents than by parents, this finding applying equally to both genders of grandparent/parent. From an evolutionary perspective, this point is to be underlined. Nepotistic effort is the salient life effort during the sunset years (Alexander Reference Alexander1987), and it therefore comes as no surprise that its practice is perceived as highly satisfying.
An impression left by the studies reviewed by C&H is that the effects of grandparental care-giving count if they have an impact on the achievement scores of grandchildren. The value of grandparenting ought not to be so narrowly defined. In addition to achievement, there is also well-being, a feeling of connectedness, happiness, and life quality, for both the grandchild and the grandparent. Objective measures (e.g., survival rates, achievement scores) as well as subjective measures need to be considered for grandparents, parents, and grandchildren.
C&H clearly describe the consequences of the demographic transition for grandparent–grandchild relationships. The shared lifespan between grandparents and grandchildren is bound to become shorter; and increasingly there is only one grandchild. We might ask whether deprivation of contact with grandchildren might have adverse effects on the life quality of the aged. I have had grandparents in my office weeping bitterly of their biggest misfortune: that they were denied contact with their only grandchild. Legislators have become sensitive towards this problem. The recognition of grandparents' visitation and custody rights is a fairly recent trend.
Also rather recent is the increased consideration of grandparents in public child welfare (Herring Reference Herring2008). Kin are increasingly used as foster parents. In the United States, the most common placement for foster care is with grandparents, usually the maternal grandmother (Scannapiego & Hegar Reference Scannapiego and Hegar2002). Legislators and welfare agencies prefer to listen to the expert advice of social scientists rather than evolutionary biologists, but the blatant disregard for biological variables may come with costs. There are asymmetries between the sexes which do not disappear by “deconstruction” or by benign neglect. If, for example, sociological studies investigate step-parent households – defined as those with either a stepmother or a stepfather – an important distinction is overlooked, namely, whether the biological parent with whom the child co-resides is the mother or the father. Mother absence is more disadvantageous to the child's development than father absence, both with respect to the investments made in children and with respect to child outcomes (Case et al. Reference Case, Lin and McLanahan2001), and parental investments are lower in stepmother families than in birth mother families (Case & Paxson Reference Case and Paxson2001). Most telling and directly relevant for grandparental care-giving are the findings by Duflo (Reference Duflo2003), who examined the flow of pensions given in South Africa to grandparents living with their grandchildren. Disturbingly, only the pensions to maternal grandmothers were channeled on to grandchildren.
The review by C&H shows that grandparental investment protects children from adverse effects in certain family situations with high risks. Risky situations may, at first glance, appear to be a matter of past epochs of famines, epidemics, and recurrent wars, or seem rare cases with little importance for normal modern families. But the list of risks, which is not exhaustive, includes maternal depression, teenage pregnancy, lone-parent, and step-parent families. These risks have such a high prevalence in modern societies that there is, and always will be, a need for helping grandparents whose assistance is good for the grandchildren – and also good for the grandparents, as long as they are not the sole caretakers. Life has been risky in the past and will remain risky in the future, even if the types of risks change with time. Therefore, contemporary grandparental care is not an evolutionary mismatch, an adaptation advantageous in ancestral environments but useless in modern times, like the hedgehog's instinct to roll itself inwards when a car approaches.