Parental investment is derived from the total amount of resources that an organism has available to use on keeping its offspring alive over the course of the parent’s lifetime. It represents any resource (such as energy, time, food, or labor, to name a few) that increases an offspring’s chance of survival at the expense of another existing or potential future offspring. As a result, offspring compete with each other for parental investment. For example, the parental investment in a glass of milk is measured by the amount that one offspring’s drinking the pint of milk reduces the life expectancy of any of that offspring’s current (or potential future) siblings. The concept of parental investment was formulated by Robert Trivers. Richard Dawkins uses the concept at length to explain behavior between related individuals, especially parents and their offspring.
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Parental Investment (PI) Term Timeline in The Selfish Gene
The timeline below shows where the term Parental Investment (PI) appears in The Selfish Gene. The colored dots and icons indicate which themes are associated with that appearance.
Chapter 8: Battle of the Generations
...favorite child that she invests in more than others. He borrows a way to measure parental investment (PI) from Trivers, who argues that parental investment is “any investment that increases the offspring’s...
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...reader already knows from Lack that she shouldn’t have too many children and spread her parental investment so thin that her young don’t survive to reproduce. But should she invest in some...
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...may be wise for the mother to reject the runt and distribute his or her parental investment among her other children. It may even be smart to kill the runt and devour...
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...it’s wise for her to save the older one, since she’ll need to expend additional parental investment to get the younger one to the older one’s age. On the other hand, if...
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...so it may be wise to try to “grab” more than one’s fair share of parental investment . Dawkins thinks this is why piglets often race to reach their nursing mother. On...
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...is whenever he or she has had his or her fair share of her lifetime parental investment ). This is likely is why children often resist weaning, but eventually accept it.
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...by way of the runt’s sibling, who becomes stronger by taking the runt’s share of parental investment .
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...general, it’s a wise strategy for children to lie and cheat to get as much parental investment as possible. A. Zahavi even speculates that some birds chirp to attract predators to their...
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...smart for cuckoos to throw the other eggs out of the nest and hog the parental investment , especially because the cuckoo is not genetically related to the other eggs in the...
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