week 8- problems of parenting and kinship Flashcards
(42 cards)
do parents of all species naturally care and love their children? what do they do then?
no, many species engage in no parental care at all, instead relying on a strategy of mass producing and releasing gametes
what is the evolutionary perspective as to why parents care for their children?
-In species where offspring could benefit from parental care, and where it is possible and economical to do it, any genes that incline individuals to take care of their own children are likely to spread through a population
-If genes promote strong/weak feelings of care for biological children, then individuals with those genes are more/less likely to act in ways that increase the
survival and reproduction of their children.
–Given that their children are likely to share those genes, the genes then become more/less likely to
persist in the next generation
Across cultures, __________ typically shoulder more of the responsibility for parental care than ________
women
men
what point of development is the sex difference in parenting (women do it more than men) most pronounced?
infancy
explain who the Israeli kibbutzim (“gathering”) are. what were tehy inspired by?
collective communities, dating back to the early 1900s
-inspired by socialism
what did the Israeli kibbutzim do in terms of child rearing?
-Wanted to liberate women from domestic duties and child-care in the name of gender equality. Also argued that it was selfish for parents to want to control their children and that they should be
allowed to develop independently.
-So, children were raised in communal children’s houses and the primary care-givers were trained nurses and teachers, not parents (who saw children 2-4 hours a day)
-However, over time, the women in the kibbutzim began to insist that their own children be allowed to
live with them.
– Despite opposition from the men, the practice of collective child-rearing was largely ended in the 1970s.
– Parenting patterns moved to the pattern seen in every other human culture
how can the parental investment theory explain why men take on less parental responsibility than women
parental uncertainty
-fertilization occurs in the female body, so the chances that she’s raising her own kid are high, this is not true for males
A gene in a female that encourages parental care has, on average, a ____ chance of being present in the offspring
50%
If there is any degree of paternity uncertainty, then there is, on average, less than a ____ chance that a gene in a male is also in the
offspring.
50%
The fitness cost to not providing care to offspring is ______ for females than for males
greater
The fitness benefit to providing care to offspring is ______ for females than for males when any
degree of paternity uncertainty is present
greater
Across species, the _______ the paternity uncertainty, the _____ the parental care that males provide (and vice versa)
higher
lower
Across species, ________ paternity uncertainty increases paternal care (male care of offspring).
reducing
how do male sunfish deal with paternity uncertainty
Sunfish Females lay their
eggs in the male’s nest. The male then fertilizes the females’ eggs (thus he is more certain to be related to the offspring). Male
sunfish then guard and “fan” the eggs
how do bonobos deal with paternity uncertainty
Females bonobos are sluts.
Thus, male bonobos experience high paternity uncertainty.
Male bonobos provide
no parental care at all
Internal pregnancy means women, but not men, are __________________________
definitely genetically related to their offspring
If paternity uncertainty reduces the likelihood of paternal investment, are heterosexual
women motivated to reduce their partner’s uncertainty? use a study to explain
Daly & Wilson (1982) examined videotapes of 111
U.S. births.
– In 40, people at the birth commented on the
baby’s resemblance to the mother or father.
– Comments on the resemblance to the father were
four times more common than to the mother,
especially among comments made by the mother.
explain the follow up birth study by Daly and Wilson that relates to paternity uncertainty
In Study 2, they sent questionnaires to new
parents (in Hamilton, Toronto, and Charlottetown)
and asked them to pass on the questions to a
relative of both the mother and father.
* 122 mothers responded
* 111 fathers
* 86 mothers’ relatives
* 66 fathers’ relatives
– Respondents were much more likely to say that
the baby resembled the father than the mother
what were the three main points that the study held true to by Daly and Wilson on paternity uncertainty
- This was true for sons and daughters (although more pronounced for sons than daughters).
- The imbalance in comments was even greater if this was the couple’s firstborn child; mothers were especially likely to comment on the resemblance to fathers for the first child.
- Parents also said that they had received comments from other people about the resemblance to the father more often than about
the resemblance to the mother
explain McLain et al. (2000)’s study about paternity uncertainty
-Interviewed parents of 1- to 3-day-old newborns in the U.S. and took photos of the newborns and their parents
-When strangers were asked to try to match 10 newborns to their parents, they were slightly better at matching newborns to their mothers than to their fathers.
what is the theory of parent child conflict
-involves a clash between how your parents want to treat siblings (equally) and how siblings want to be treated (preferentially)
-For parents, each child shares 50% of their genes. Parents’ genes will spread more effectively if they incline the parents to treat
their children roughly equally.
-For each child, they have 100% of their own genes (obviously), but their siblings only share (on average) 50% of those genes.
-So, in the children, genes would spread more effectively if they led each child to prioritize itself more than its sibling(s). From the perspective of genes in the children, any investment in the child is guaranteed (100%) to increase the odds those genes make it to the next generation, but any investment in a sibling has only a 50% chance of increasing the odds those genes make it (because there is only a 50% chance that any one gene of the
child’s is present in the sibling)
there would have been
selection pressure for parents to treat children relatively _________ than children themselves will want; children will have been under selection pressure to want more for themselves than for their siblings
more equally
what does inclusive fitness mean?
Genes are likely to become more widespread if they not only encourage you to survive and reproduce, but also if they encourage you to assist the survival and reproduction of your genetic relatives
what is the calculation of inclusive fitness. explain.
direct fitness + indirect fitness
direct fitness is an individuals own reproductive success, while indirect fitness is the reproductive success of an individuals relatives WEIGHTED BY THEIR RELATEDNESS to the individual
