Mayra Lavadenz

Martha Gomez

Rachel Stern

James Sweeny

 

Hrdy, Sarah Blaffer.  Mother nature:  a history of mothers, infants, and natural selection. 

New York:  Panteon Books, 1999.

 

What is the optimal number of fathers?  The answer to this question varies depending on whom you ask.  Hrdy explores this question in chapter 10 of her book, Mother Nature.  The biggest reason for the varying answers to this simple question is due to the differences in how each gender can maximize his or her reproductive success.  Hrdy looks at this question by exploring the benefits and consequences found for different situations in which the number of fathers varied. 

First she looks at being fatherless.  She says having zero fathers is difficult for reproductive success because of numerous disadvantages, which include “economic hardships, reduced status, and declining prospects” (Hrdy, 1999, p. 235).  According to Hrdy, children in fatherless families do worst in school, and boys show higher crime rates, whereas girls have earlier pregnancies.  Furthermore, fatherless children in foraging societies are four times more likely to die.  Due to these detrimental results, many foraging societies are accustomed to burying living children with their dead father.

Some parents, especially in western societies, opt for a less barbaric alternative to raising a fatherless child; they find a stepfather for the child.  Hrdy believes this alternative is actually worse for young children.  “In North America when the father of offspring under two years of age no longer lives in the home and an unrelated man or stepfather lives there instead, [child homicide] is seventy times more likely to occur” (Hrdy 236).  Hrdy says this is probably not due to a human evolutionary mechanism, as is the case with other animals.  In other animals, males kill the offspring of their new mates. They kill offspring that has been sired by other males in order to increase their own reproductive success.  Hrdy believes the causes of death are more likely due to the fact that the new father does not have much tolerance for the demands of the crying infant, causing him to be too rough with the baby while trying to quiet it.  Although, in these instances humans do not exhibit the same reason for infanticide as other animals do, in some circumstances stepfathers do show the behavior of intentional infanticide.

She says this usually occurs in societies where men from one village kidnap women from other villages.  These women are abducted because the men are competing for the limited resource of fertile females.  Not only do the raiders take the women and leave the children behind, many times they kill the children as well.  Hrdy is not really sure why these men kill the infants, particularly because the ability of the woman to be fertile and devoted to raising new offspring are the same, regardless of whether previous children are killed or not.  Nonetheless, these men target children, especially male children.  She says that men may have some programming for this behavior because of similar behavior in chimpanzees and gorillas, but that men calculate whether or not it is worth keeping a certain children alive or not.  Though not conscious of the calculation, the equation used is Hamilton’s rule Cost < Benefit x Relatedness.

All of these situations show that it is importance for fathers to stay around.  Hrdy thinks that the costs of not having a father has led to the evolution of mechanisms in women in which they find certain qualities attractive in men.  In one study, women in more than 30 countries ranked valuable traits for a husband, other than mutual attraction.  The top ranked traits were dependable character, emotional stability and maturity.  Some people find it surprising that selecting for physical qualities are not as highly ranked.  Hrdy says this is because children with a father that does not stay around will die no matter how powerful the physical characteristics inherited by the child.  So traits that indicate the man will stay and help raise the child are more desirable.  (Hrdy, 1999, p. 245)

Now she goes into looking at what happens with a fraction of a father.  A child will have a fraction of a father in patriarchal societies.  A child will have a fraction of a father when one man marries several women.  These arrangements occur when males monopolize the resources and in turn use the resources to monopolize the females.  Hrdy believes this behavior first developed in order to insure paternity of children.  For example, in the Dogon society, men can have as many wives as they can afford.  In some extreme forms of this type of culture, paternity is further insured because females must report to a hut when their menstrual cycle starts.  This is to ensure that the men know they are not marrying a pregnant woman.  This type of lifestyle is very beneficial to the male reproductive output but not for the female’s reproductive output.  It is also not a good setup for the children; Hrdy gives two reasons for this.  Even though men have paternity security they still do not invest much in the children.  Instead, they try to increase their status and get more women.  Second, Hrdy states that there is competition between women because the father only leaves inheritance to a few sons.  Consequently, mothers will sometimes poison other sons.  Hrdy also points out that in this society 46% of children will die before they reach five years old.  Even more noteworthy is that children born in rich polygynous families are seven to eleven times more likely to die than children born in poor monogamous families.  According to Hrdy, the reason for this is that if a man has three wives and loses half his children he will still come out ahead than if he had only one wife and all his children lived.  For monogamous families the man’s loss is equal to the woman’s loss so he will invest more in keeping the children alive.  (Hrdy, 1999, p. 255)

Many psychologists believe that this setup is beneficial for both sexes because the woman gets to choose whether she wants to marry a rich man with multiple wives or if she wants to marry a poor man and be the only wife.  This reasoning is supported by the behavior of some animals.  Where the males will fight over territory, the strongest males will get the best territory.  Then when the females come along they can choose which territory they want.  In order for this argument to work you have to assume that the men control the resources.  Hrdy says that if you take into account that the women could control some resources, this setup is not beneficial.  Now that we know polygyny is a detriment to women’s reproductive ability, the question Hrdy raises is, why would mothers accept such poor terms?

Most primates solve this problem by using violence.  However, a much more “insidious” method is used in human societies.  Human societies use the human imagination as the tool.  First there is gossip about how women act and the “sexual conduct of women” (Hrdy, 1999, p. 259).  This gossip is used to keep women from doing anything socially unacceptable.  Another method is by setting up gender roles.  Hrdy says the typical role for women is to be modest, chaste and a good mother.  Another method used to convince women of these terms is to use superstition or religion.  Hrdy gives an example found in Mexico and Central America, in which women believe that if they are immodest or even if they break any taboos like cooking during the duration of menstruation, then h’ik’al will carry them off to his cave and rape them.  (Hrdy, 1999, p. 259)  Once that happens the woman gives birth every night until she dies.  Finally, in these cultures and in most cultures around the world, the status of children is partly decided by the virtue of the mother.  We will now look at what happens when a child has more than one father.

Matrilineal societies usually have children with more than one father.  Matrilineal societies are when the inheritance is passed from the mother’s brother to the mother’s son.  A matriarchal society is one where women control the resources.  According to Hrdy, throughout human history there has never been a matriarchal society and there are few matrilineal societies existing now.  She believes this is because it is easier for men to hold on to land than it is for women.  This type of society is used for foraging societies where food is unpredictable and there is a high adult male mortality rate.  The unpredictability of food and providers gives rise to the need for women to acquire several fathers.  Consequently, if one father fails at getting food, the others will still be able to feed her and her children.  An example of this can be found in the Ache people.  These people have an average of two fathers for every child.  There is a common belief usually found in matrilineal societies that helps fathers accept feeding responsibilities for a child that is not theirs.  They believe that fetuses are “built up over time”, by multiple men who have had sexual relations with the mother.  (Hrdy, 1999, p. 246)  In these cultures the husband is considered the primary father of the child while other men, with whom the woman had relations, are considered secondary fathers.  “All men with whom a woman had sex when she became pregnant, including the period just prior to when she was detectably pregnant, are expected to provide food for her and her child” (Hrdy, 1999, p. 247). 

With that said, as soon as women think they are pregnant they try to seduce the best hunters and fishers in the village.  For the Ache culture, 46% of children with a single father die before age 15, whereas only 20% of children with multiple fathers die before age 15.   In the Ache culture women must be careful not to acquire too many fathers because then nobody will want to invest in the child.  However, in Canela the resources are so unpredictable that women are encouraged to honor a custom where women have “ritual sex with twenty or more men during all community ceremonies” (Hrdy, 1999, p. 249).  This culture is more beneficial to the women, because women get to maximize their reproductive output and ensure providers of food for their children.  These cultures are not very common because as soon as people start making life more predictable by using currency or agriculture, there is no more need for many men to take care of a child.  This predictability usually shifts the culture to a patriarchal one.

Finally Hrdy briefly mentions monogamy, or having a single father.  She does not go into much detail but she does say that monogamy is a stable state and that it is stable because of the high survival rate of the children.

 

 

OUTLINE

 

I.                    The optimal number of Fathers

a.       It depends

                                                               i.      Differences in how each gender can maximize his or her reproductive success

                                                             ii.      Benefits and consequences found for different situations in which the number of fathers varied. 

 

b.      Zero Fathers

                                                               i.      Numerous disadvantages

1.      economic hardships,

2.      reduced status,

3.      declining prospects

4.      children do worst in school,

5.      boys show higher crime rates,

6.      girls have earlier pregnancies

                                                             ii.      Fatherless children in foraging societies

1.      Four times more likely to die. 

a.       Accustomed to burying living children with their dead father.

                                                            iii.      Fatherless children in western societies

1.      Find a stepfather for the child

a.       actually worse for young children

b.      child homicide 70 times more likely

c.       not evolutionary mechanism

d.      other animals, males kill the offspring of their new mates.

                                                                                                                                       i.      increase their own reproductive success.

e.        Cause of death for humans

                                                                                                                                       i.      Inexperienced fathers are too rough with child

2.      In some circumstances stepfathers do show the behavior of intentional infanticide.

 

c.       Intentional infanticide

                                                               i.      usually occurs in societies where men from one village kidnap women from other villages. 

1.      women are abducted because they are a limited resource.

2.       Raiders:

a.       take the women and leave child behind,

b.      and kill the children as well. 

3.      Why do these men kill the infants?

a.       Women can be fertile and devoted even when prior children are alive

b.      Even still, men target children, especially males.

c.       men may have some programming--similar to  chimpanzees and gorillas,

                                                                                                                                       i.      Men also calculate:  Hamilton’s rule Cost < Benefit x Relatedness.

 

d.      Importance of having a father who is present

                                                               i.      evolution of mechanisms in women in which they find certain qualities attractive in men.

                                                             ii.      The top ranked traits

1.      dependable character,

2.      emotional stability

3.      and maturity. 

                                                            iii.      Surprisingly, selection for physical qualities are not as highly ranked. Why?

1.      because children with a father who is not around will die no matter how powerful the physical characteristics inherited by the child.

2.      So traits that indicate the man will stay and help raise the child are more desirable.  (Hrdy, 1999, p. 245)

 

II.                 Having a fraction of a father in patriarchal societies

a.       A child will have a fraction of a father when one man marries several women

                                                               i.      This happens when males monopolize the resources and use that to monopolize the females

                                                             ii.      This first came about to ensure paternity of the children

1.      One example is the Dogon society, where men can have as many wives as they can afford

b.      In extreme forms of patriarchal societies, paternity is ensured because females must report to a hut when their menstrual cycle begins so that men know they are not marrying a pregnant woman

                                                               i.      This is beneficial to the male reproductive output but not the female reproductive output because of two reasons:

1.      Men may have paternity security but they still do not invest much in the children, instead trying to increase their status and gain more women

2.      There is competition between women because the father leaves inheritance to only a few sons

a.       In these types of societies, 46% of children will die or be killed before they reach five years of age

b.      In rich polygynous families, children are 7-11 times more likely to die than children in poor monogamous families

                                                                                                                                       i.      This is due to the fact that in monogamous families, the man’s loss is equal to the woman’s loss if children die, so he will invest more in keeping children alive than a rich polygynous man would, because he could always have more children with his multiple wives

c.       Multiple spouses can be beneficial for both sexes because the woman gets to choose whether she wants to marry a rich man with multiple wives or a poor man and be the only wife

                                                               i.      This is supported by animal behaviors

1.      When males fight over territory, the strongest male wins the best territory.  Females then come and choose which territory they want

a.       This argument only works if you assume that men control the resources.  If women control the resources then this does not work.

III.               Why do mothers accept such poor terms for their children?

a.       Humans use the imagination to solve this problem

                                                               i.      There is gossip about how women act and the “sexual conduct of women” (Hrdy 259).  This gossip is used to keep women from doing anything socially unacceptable. 

                                                             ii.      Another way of doing this is setting up gender roles.

                                                            iii.      Another method used to convince women of these terms is to use superstition or religion. 

1.      Example: a belief in Mexico and Central America.  Women believe that if they are immodest or even if they break any taboos like cooking during the duration of menstruation, then h’ik’al will carry them off to his cave and rape them.  Once that happens the woman gives birth every night until she dies.

                                                           iv.      Finally, in these cultures and in most other cultures around the world, the status of children is partly decided by the virtue of the mother. 

IV.              What happens when a child has more than one father

a.       Matrilineal societies

                                                               i.      Usually have children with more than one father.

                                                             ii.      Matrilineal societies are when the inheritance is passed from the mother’s brother to the mother’s son. 

                                                            iii.      A matriarchal society is one where women control the resources.

1.      This type of society is used for foraging societies where food is unpredictable and there is a high adult male mortality rate.  The unpredictability of food and providers gives rise to the need for women to acquire several fathers.  If one father fails at getting food, the others will still be able to feed her and her children. 

a.       Example: the Ache people.  They have an average of two fathers for every child.  There is a common belief usually found in matrilineal societies that helps fathers accept feeding responsibilities for a child that is not theirs.  They believe that the child is built by multiple men who had sexual relations with the mother.  In these cultures the husband is considered the primary father of the child while other men, with whom the woman had relations, are considered secondary fathers.

b.      Benefits of multiple fathers

                                                               i.      For the Ache culture 46% of children with a single father die before age 15 but only 20% of children with multiple fathers die before age 15.  

1.      In the Ache culture women must be careful not to acquire too many fathers because then nobody will want to invest in the child.

                                                             ii.      In Canela the resources are so unpredictable that women are encouraged to honor a custom where women have “ritual sex with twenty or more men during all community ceremonies” (Hrdy 249). 

1.      This is more beneficial to the women

a.       They get to maximize their reproductive output and ensure providers of food for their children.

                                                            iii.      These cultures are not very common

1.      When people start making life more predictable by using currency or agriculture there is no more need for many men to take care of a child.  This predictability usually shifts the culture to a patriarchal one.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Critical Review

 

Identify up to three points made by the author that the panel found especially interesting or informative. 

 

1)      I found it very interesting that having a stepfather in the home actually increases the risk to young children.  I thought that a stepfather would be another provider and so the child would be better taken care of and not put at more risk.

2)      It was very interesting to hear that some cultures believe a fetus is formed from a conglomeration of semen from different men. 

3)      I think it is interesting how even though males have paternity security they still do not invest much in the children.  They are more concerned with gaining status by having more wives.  Wouldn’t it make sense that if they invested in their children, then more children would survive and help the males have high status?  It seems that the more children a man had, the higher his status would be. 

 

Identify up to three augments made by the author that the panel either disagreed with and/or for which you think the author made a weak case.  Why? 

 

1)      The author made a weak case for monogamy being very stable and when specifically it would be stable because it seems to me like monogamy in areas where resources are scare would give children a lower survival rate than those with more than one father.  So I don’t know if I agree that monogamy is as stable as Hrdy makes it out to be.

2)      Hrdy believes that stepfathers kill step children because they are inexperienced, and not because they are have an evolutionary mechanism that drives them, but she later contradicts this by the example of the raiders who kill the children of the women they kidnap.

3)      I don’t understand why Hrdy thinks that having multiple fathers for children developed to insure paternity of children.  That is confusing.

 

Identify up to three concepts that, even after reading the material, the panel still had questions about, or that the panel would have liked the author to have explained further. 

 

1)      I have a question about the areas where children have more than one father.  The data showed that children in these resource poor areas did better if they had two fathers rather than just one.  The explanation Hrdy gave for this phenomenon is that two fathers will give the child more food than if the child only had one father.  But presumably the number of men and women in these areas are probably close to equal so if most children in that society have more than one father to take care of them then it seems like the fathers will have more children from several women to take care of.  So even though more than one man provides for the child each man has to give each individual child less because he has to give to a greater number of children than he would if he had only one child to care for.  So she needs to further explain why the greater number of fathers per child and the greater number of children per father do not cancel out.

2)      Hrdy should go into further detail on monogamy, and the consequences of having one father

3)      I think Hrdy should have gone into more detail about how even if males have paternity security, they still may not invest in the child. 

 

Test Questions

 

In situations when a stepfather comes into a home with a young child, in the western culture.

 

A:  The child has a better chance of survival because now there are two parents to take care of it.

B:  The child has about the same chance of survival because stepfathers don’t normally take care of their stepchildren.

C:  The child has a lower chance of survival because the stepfather will kill the child to increase his own reproductive success

D:  The child has a lower chance of survival because the stepfather has a low tolerance level for an annoying young child and will sometimes accidentally kill the child.

E:  The child has a lower chance of survival because the stepfather is more likely to give resources to his own children than to the stepchild.

 

Answer D

 

Hrdy says _____________ is a surprisingly stable number of fathers because of the high survival rate of the children.

A:  Zero Fathers

B:  Stepfather

C:  Fraction of a father

D:  One father

E:  More than one father

 

Answer D

 

When a child is fatherless, its chances of survival are minimized because of

 

A:  Economic hardship

B:  Reduced status

C:  Declining prospects

D:  All of the above

 

In some societies, paternity is ensured because females report to a hut when their menstrual cycle begins so men know they are not marrying a pregnant woman.  This is beneficial to male reproductive output but not female reproductive output because:

 

A:  Men have paternity security but do not invest in the children, instead increasing their status by gaining more women

B:  The men want to impregnate the women themselves, instead of acting as a father to another man’s child

C:  There is competition between women because the father leaves inheritance to only a few sons

D:  Both a and b

 

Both D

 

 A __________ is a society in which women control the resources.

 

Matriarchal society

 

In societies where resources are unpredictable the most children survive when they have one father, because they are insured that this father will provide for them and not spread his resources too thin.

 

Answer False

 

One of the circumstances in which men show intentional infanticide occurs when women are kidnapped from their village, and the raiders kill these women’s children. 

 

Answer True

 

Men are said to have a programming in which they calculate whether or not it is worth keeping a certain child, which is an unconscious calculation of Hamilton’s rule, Cost < Benefit x Relatedness. 

 

Children will have a fraction of a father when one man marries several women.  This happens when males monopolize the resources and use this to monopolize the females.

 

Answer True

 

In families with a stepfather, the chance for child homicide is greater.

 

Answer True