Are humans cooperative breeders? [2]
"Given the high diversity of ecological and social environments within which humans are currently found, specific human groups, populations, or cultures, rather than the human species as a whole, should be considered as units for comparison, analysis, and discussion." (Crespi 2014; also see Jones 2011)
Based upon Sarah Blaffer Hrdy's influence, it has become fashionable in the literature of Anthropology, to term [and, by implication, to classify] humans as "cooperative breeders". The purpose of this blogpost is to highlight Crespi's (2014) recent treatment of this topic and to provide, hopefully, constructive criticism of the topic's most recent discussion (Kramer & Russell 2015). In particular, I will make explicit certain untested assumptions underlying the classification as well as an apparent misunderstanding and/or mis-application of Hamilton's rule. This diagnosis is not intended to be exhaustive; however, it is my opinion that the concerns raised here provide a framework for necessary research to be conducted before the variety and range of conformations of human reproductive units can be described, including, traits associated with different conformations within and between populations.
In particular, I wish to stress that allomothering/alloparenting may be imposed by exploitation in the form of, for instance, coercion or social parasitism by reproductives [mothers] upon Donors [Actors, "helpers", "allomothers"] and that, rather than benefiting reproductive interests of Recipients [mothers] AND Donors ["helpers", "alloparents", "allomothers"], as per Cooperation, apparent "cooperation" may be deleterious to Donors/"allomothers" who may exhibit Altruism and/or apparent "cooperation" may be induced/imposed by Selfish behaviors on the part of Recipients [mothers], e.g., via coercion, including, in some cases, manipulation via financial reward.
Kramer & Russell (2015) recently addressed monogamy as a possible precursor to "cooperative breeding" in humans, explicating, clearly, and without qualification, the current, accepted argument[s] in Anthropology for classifying, without qualification, the human species as "cooperative breeders" [see epigram to this blogpost]. The following issues of concern pertain to the aforementioned paper and to Hrdy's earlier claims (Hrdy 1999, 2005, 2009 cited in Crespi 2014 and Kramer & Russell 2015 [subsequently, K&R]).
1. K&R define "social [sic] breeding systems" as "cooperative breeders" exhibiting "two key characteristics" [pg 74]: (1) "those individuals who provide care to the offspring of others [and are] currently non-breeders" and (2) "helping behaviors may be directed to another's offspring or toward mothers or other caretakers, which facilitates increased investment in offspring now or in the future." There is little consensus among researchers about what characterizes "cooperative breeding"; thus, the criteria advanced by K&R require comparative analysis and may be considered tentative hypotheses. An obvious problem confronting the aforementioned two criteria is that many species not classified as "cooperative breeders" meet the two conditions [e.g., grooming or "allomothering" in many primate and social carnivore taxa such as macaques, baboons, wild dogs, and hyenas or numerous "communal" rodents].
2. Throughout K&R, and much [all?] of the literature on [apparent, ostensible] "cooperation" in the Anthropology literature, apparent, ostensible "cooperation" is assumed to be a positive interaction [facilitation]. This is a non-trivial, untested and implicit assumption. "Helping" cum "cooperation" requires measurement or estimation of differential [reproductive] costs and benefits associated with "allomothering" behaviors [traits] before we can label these interactions "cooperative". Further, Cooperation may be imposed upon Donors ["helpers", "allomothers"] by Recipients [mothers] by a wide range of exploitation and manipulation [negative interactions], such as coercion, force, persuasion, social parasitism, shaping, and/or financial reward.
3. Related to #2 above, K&R, and other Anthropologists, appear to assume that benefiting kin is generally, if not always, advantageous to Donor [mother]. This assumption suggests a fundamental misunderstanding of Hamilton's Rule which does not state that benefits to [potential] Donor will always be + since costs of doing so may be prohibitively high. This fundamental error highlights the importance of measuring or estimating differential costs and benefits to Donor ["allomother"] and Recipient [mother] alike.
On the other hand, induced or imposed [potential] costs to [potential] Donor may make it beneficial for Donor to "help" where it is not possible for [potential] Donor to escape costs, such as, where response[s] to [potential] Recipient [mother or other self-interested group member"/imposer" of costs] are not under [potential] Donor's ["allomother's"] control. [Reproductive] costs from NOT "helping"/"allomothering" may be prohibitively high for [potential] Donor if s/he can not escape control by [potential] Recipient [mother].
4. After K&R, "Humans live in multi-male, multi-female groups that include multiple breeding females who often reside within socially recognized, long-term monandrous unions." [p 75]. These conditions may characterize some other mammalian groups, populations, or taxa, a topic that remains unstudied systematically.
5. Two additional criteria that have not, to my knowledge, been addressed by Anthropologists relative to their classification of humans as "cooperative breeders" is the extent to which the moniker requires high "skew" in groups and totipotent "helpers" [non-reproductive "allomothers" who may revert, in a condition-dependent, situation-dependent manner, to reproductives]. Should the latter trait be agreed upon as a diagnostic trait for classification of a group or population to be considered "cooperatively-breeding", menopausal females [often assumed to be grandmothers] and pre-reproductive offspring would not be considered diagnostic for said classification. See, for example, literature on "cooperatively-breeding" callitrichids for diagnostic use of high "skew" and totipotency, in addition, to employment of these terms in literature on Social Insects (see, also, Crespi 2014).
6. I am not aware of any quantitative [especially, modelling or theoretical] treatments of the above topics nor of experiments [lab, naturalistic, agent-based modeling] on the aforementioned matters in the Anthrropology literature.
7. I intend for the previous comments to convince the reader of the need for additional research within and between human groups in order to systematically evaluate the range and varieties of reproductive units in humans, a species with noteworthy facultative behavioral responses (see Jones 2011 and "Are humans cooperative breeders? [1], this Blog, as well as epigram above from Crespi 2014; also see Crespi 2009).
8. Following the epigram to this blogpost and related literature cited, it is clear that it is ill-advised to label humans as a species characterized by a single "breeding" system. Furthermore, without further evidence, it is not clear that "cooperative breeding" is the norm in most human populations over time and space. Related to this, there is no consensus among mainstream researchers concerning diagnostic criteria for a cooperatively-breeding group or population.
9. In accord with the call for additional research, there is a need to evaluate the literature on deleterious effects of "allo"-carers upon dependent human young. For example, male caretakers may injure or kill young at alarming rates in human groups and populations. Presumed benefits of grandmothers may be exaggerated and their deleterious effects may be minimized.
10. In 1999 (Jones & McJetters 1999), I wrote the following as a Note [p 123, #s 2 & 3] in a paper about women on death row. The statement suggests ways to quantitatively address the Socioecology of Co[-]operative Breeding in Humans. The significance of the Notes is unrelated to the topic of the paper [women on death row]. One significance of the Notes is to highlight Crespi's (2014; Jones 2011) statement above [epigram to this blogpost]...human mating systems are expected to vary, and the causes and consequences of such variation may differ as a function of, say, SES [class], race, etc. Another point of interest [Note 3] is expected to be the dynamics of interactions between mothers and potential or actual mates.
Note 2: "We believe that Emlen's (1995) ecological model of the family will facilitate the analysis of behavioral differences between Black and White women, including differences in violent behavior. Emlen's ecological model predicts cooperative family organization (e.g., extended families) in regimes where independent breeding is uncertain, as is the case for many Black females. Where independent breeding is more reliable, as it may be for most White women, individualistic strategies are predicted. Ray & Smith (1991, p 150) also note the importance of ecological models for analyzing the consequences of differential access to resources in time and space for homicidal behavior. Ecological models are potentially of value to the student of violence because they are sensitive to interindividual competition for limiting resources."
Note 3: "A complicating factor, however, is that the profile of Black female homicide offenders is expected to be tied to that of Black males, since ecological theory predicts that female behavior will be a function of their resource base, including potential investment by males in herself, her childre, and her kin. Since the social and economic status of Black males is expected to be lower on average than that of White males, the causes and consequences of criminal behavior by Black and White women may continue to differ significantly."
Crespi (2009)
http://www.sfu.ca/biology/faculty/crespi/pdfs/122-Crespi2009SkewTheory.pdf
Crespi (2014)
http://www.sfu.ca/biology/faculty/crespi/pdfs/168-Crespi2013HumanNature.pdf
Emlen (1978)
Emlen ST (1978) The evolution of cooperative breeding in birds. In: Krebs JR, Davies NB, Behavioural ecology: an evolutionary approach. Blackwell, UK.
Hrdy (1976)
https://books.google.com/books?hl=en&lr=&id=x_hfmoOaHpoC&oi=fnd&pg=PA101&dq=sb+hrdy++1976&ots=IrAlXVg1ae&sig=OZrcPETIUNcFezBBbxBVssldVR4#v=onepage&q&f=false
Jones (1986)
http://onlinelibrary.wiley.com/doi/10.1002/1098-2337(1986)12:3%3C167::AID-AB2480120303%3E3.0.CO;2-X/abstract
Jones (2011)
http://link.springer.com/article/10.1007/s10508-011-9741-5#page-1
Jones CB, McJetters Y. (1999) Gender, race, and homicide: a preliminary analysis. The Western J of Black Studies 23:2, 119-124.
Kramer & Russell (2015)
http://onlinelibrary.wiley.com/doi/10.1002/evan.21445/abstract
Solomon & French (1997)
Solomon NG, French JA (1997) Cooperative breeding in mammals. CUP, UK.
"Given the high diversity of ecological and social environments within which humans are currently found, specific human groups, populations, or cultures, rather than the human species as a whole, should be considered as units for comparison, analysis, and discussion." (Crespi 2014; also see Jones 2011)
Based upon Sarah Blaffer Hrdy's influence, it has become fashionable in the literature of Anthropology, to term [and, by implication, to classify] humans as "cooperative breeders". The purpose of this blogpost is to highlight Crespi's (2014) recent treatment of this topic and to provide, hopefully, constructive criticism of the topic's most recent discussion (Kramer & Russell 2015). In particular, I will make explicit certain untested assumptions underlying the classification as well as an apparent misunderstanding and/or mis-application of Hamilton's rule. This diagnosis is not intended to be exhaustive; however, it is my opinion that the concerns raised here provide a framework for necessary research to be conducted before the variety and range of conformations of human reproductive units can be described, including, traits associated with different conformations within and between populations.
In particular, I wish to stress that allomothering/alloparenting may be imposed by exploitation in the form of, for instance, coercion or social parasitism by reproductives [mothers] upon Donors [Actors, "helpers", "allomothers"] and that, rather than benefiting reproductive interests of Recipients [mothers] AND Donors ["helpers", "alloparents", "allomothers"], as per Cooperation, apparent "cooperation" may be deleterious to Donors/"allomothers" who may exhibit Altruism and/or apparent "cooperation" may be induced/imposed by Selfish behaviors on the part of Recipients [mothers], e.g., via coercion, including, in some cases, manipulation via financial reward.
Kramer & Russell (2015) recently addressed monogamy as a possible precursor to "cooperative breeding" in humans, explicating, clearly, and without qualification, the current, accepted argument[s] in Anthropology for classifying, without qualification, the human species as "cooperative breeders" [see epigram to this blogpost]. The following issues of concern pertain to the aforementioned paper and to Hrdy's earlier claims (Hrdy 1999, 2005, 2009 cited in Crespi 2014 and Kramer & Russell 2015 [subsequently, K&R]).
1. K&R define "social [sic] breeding systems" as "cooperative breeders" exhibiting "two key characteristics" [pg 74]: (1) "those individuals who provide care to the offspring of others [and are] currently non-breeders" and (2) "helping behaviors may be directed to another's offspring or toward mothers or other caretakers, which facilitates increased investment in offspring now or in the future." There is little consensus among researchers about what characterizes "cooperative breeding"; thus, the criteria advanced by K&R require comparative analysis and may be considered tentative hypotheses. An obvious problem confronting the aforementioned two criteria is that many species not classified as "cooperative breeders" meet the two conditions [e.g., grooming or "allomothering" in many primate and social carnivore taxa such as macaques, baboons, wild dogs, and hyenas or numerous "communal" rodents].
2. Throughout K&R, and much [all?] of the literature on [apparent, ostensible] "cooperation" in the Anthropology literature, apparent, ostensible "cooperation" is assumed to be a positive interaction [facilitation]. This is a non-trivial, untested and implicit assumption. "Helping" cum "cooperation" requires measurement or estimation of differential [reproductive] costs and benefits associated with "allomothering" behaviors [traits] before we can label these interactions "cooperative". Further, Cooperation may be imposed upon Donors ["helpers", "allomothers"] by Recipients [mothers] by a wide range of exploitation and manipulation [negative interactions], such as coercion, force, persuasion, social parasitism, shaping, and/or financial reward.
3. Related to #2 above, K&R, and other Anthropologists, appear to assume that benefiting kin is generally, if not always, advantageous to Donor [mother]. This assumption suggests a fundamental misunderstanding of Hamilton's Rule which does not state that benefits to [potential] Donor will always be + since costs of doing so may be prohibitively high. This fundamental error highlights the importance of measuring or estimating differential costs and benefits to Donor ["allomother"] and Recipient [mother] alike.
On the other hand, induced or imposed [potential] costs to [potential] Donor may make it beneficial for Donor to "help" where it is not possible for [potential] Donor to escape costs, such as, where response[s] to [potential] Recipient [mother or other self-interested group member"/imposer" of costs] are not under [potential] Donor's ["allomother's"] control. [Reproductive] costs from NOT "helping"/"allomothering" may be prohibitively high for [potential] Donor if s/he can not escape control by [potential] Recipient [mother].
4. After K&R, "Humans live in multi-male, multi-female groups that include multiple breeding females who often reside within socially recognized, long-term monandrous unions." [p 75]. These conditions may characterize some other mammalian groups, populations, or taxa, a topic that remains unstudied systematically.
5. Two additional criteria that have not, to my knowledge, been addressed by Anthropologists relative to their classification of humans as "cooperative breeders" is the extent to which the moniker requires high "skew" in groups and totipotent "helpers" [non-reproductive "allomothers" who may revert, in a condition-dependent, situation-dependent manner, to reproductives]. Should the latter trait be agreed upon as a diagnostic trait for classification of a group or population to be considered "cooperatively-breeding", menopausal females [often assumed to be grandmothers] and pre-reproductive offspring would not be considered diagnostic for said classification. See, for example, literature on "cooperatively-breeding" callitrichids for diagnostic use of high "skew" and totipotency, in addition, to employment of these terms in literature on Social Insects (see, also, Crespi 2014).
6. I am not aware of any quantitative [especially, modelling or theoretical] treatments of the above topics nor of experiments [lab, naturalistic, agent-based modeling] on the aforementioned matters in the Anthrropology literature.
7. I intend for the previous comments to convince the reader of the need for additional research within and between human groups in order to systematically evaluate the range and varieties of reproductive units in humans, a species with noteworthy facultative behavioral responses (see Jones 2011 and "Are humans cooperative breeders? [1], this Blog, as well as epigram above from Crespi 2014; also see Crespi 2009).
8. Following the epigram to this blogpost and related literature cited, it is clear that it is ill-advised to label humans as a species characterized by a single "breeding" system. Furthermore, without further evidence, it is not clear that "cooperative breeding" is the norm in most human populations over time and space. Related to this, there is no consensus among mainstream researchers concerning diagnostic criteria for a cooperatively-breeding group or population.
9. In accord with the call for additional research, there is a need to evaluate the literature on deleterious effects of "allo"-carers upon dependent human young. For example, male caretakers may injure or kill young at alarming rates in human groups and populations. Presumed benefits of grandmothers may be exaggerated and their deleterious effects may be minimized.
10. In 1999 (Jones & McJetters 1999), I wrote the following as a Note [p 123, #s 2 & 3] in a paper about women on death row. The statement suggests ways to quantitatively address the Socioecology of Co[-]operative Breeding in Humans. The significance of the Notes is unrelated to the topic of the paper [women on death row]. One significance of the Notes is to highlight Crespi's (2014; Jones 2011) statement above [epigram to this blogpost]...human mating systems are expected to vary, and the causes and consequences of such variation may differ as a function of, say, SES [class], race, etc. Another point of interest [Note 3] is expected to be the dynamics of interactions between mothers and potential or actual mates.
Note 2: "We believe that Emlen's (1995) ecological model of the family will facilitate the analysis of behavioral differences between Black and White women, including differences in violent behavior. Emlen's ecological model predicts cooperative family organization (e.g., extended families) in regimes where independent breeding is uncertain, as is the case for many Black females. Where independent breeding is more reliable, as it may be for most White women, individualistic strategies are predicted. Ray & Smith (1991, p 150) also note the importance of ecological models for analyzing the consequences of differential access to resources in time and space for homicidal behavior. Ecological models are potentially of value to the student of violence because they are sensitive to interindividual competition for limiting resources."
Note 3: "A complicating factor, however, is that the profile of Black female homicide offenders is expected to be tied to that of Black males, since ecological theory predicts that female behavior will be a function of their resource base, including potential investment by males in herself, her childre, and her kin. Since the social and economic status of Black males is expected to be lower on average than that of White males, the causes and consequences of criminal behavior by Black and White women may continue to differ significantly."
Crespi (2009)
http://www.sfu.ca/biology/faculty/crespi/pdfs/122-Crespi2009SkewTheory.pdf
Crespi (2014)
http://www.sfu.ca/biology/faculty/crespi/pdfs/168-Crespi2013HumanNature.pdf
Emlen (1978)
Emlen ST (1978) The evolution of cooperative breeding in birds. In: Krebs JR, Davies NB, Behavioural ecology: an evolutionary approach. Blackwell, UK.
Hrdy (1976)
https://books.google.com/books?hl=en&lr=&id=x_hfmoOaHpoC&oi=fnd&pg=PA101&dq=sb+hrdy++1976&ots=IrAlXVg1ae&sig=OZrcPETIUNcFezBBbxBVssldVR4#v=onepage&q&f=false
Jones (1986)
http://onlinelibrary.wiley.com/doi/10.1002/1098-2337(1986)12:3%3C167::AID-AB2480120303%3E3.0.CO;2-X/abstract
Jones (2011)
http://link.springer.com/article/10.1007/s10508-011-9741-5#page-1
Jones CB, McJetters Y. (1999) Gender, race, and homicide: a preliminary analysis. The Western J of Black Studies 23:2, 119-124.
Kramer & Russell (2015)
http://onlinelibrary.wiley.com/doi/10.1002/evan.21445/abstract
Solomon & French (1997)
Solomon NG, French JA (1997) Cooperative breeding in mammals. CUP, UK.