week 7 Flashcards
(25 cards)
Caspi et al. (2002)
and key finding
Studied how a gene (MAOA) affects antisocial behavior after childhood abuse.
Key Finding: Low MAOA + maltreatment = higher risk of antisocial behavior.
Differential Susceptibility
People react differently to the same environment due to their genes.
Types of Gene × Environment (G × E) Interactions
Passive
Genes match the environment (e.g., smart parents have more books).
Types of Gene × Environment (G × E) Interactions
Reactive/Evocative:
Genes affect how others treat you (e.g., attractive kids get treated differently).
Types of Gene × Environment (G × E)
Interactions
Active:
People seek environments that fit their traits (e.g., athletic kids hang out together).
Candidate Genes
a gene that is thought to be linked to a specific trait, such as a disease or physical characteristic
GWAS (Genome-Wide Association Studies):
Scan entire genome (the complete set of DNA) for trait links, but effects are usually very small and involve many genes.
Altruism
behaviors that benefit others, often at a cost to oneself
inclusive fitness
Inclusive fitness is the total success of an individual in passing on their genes, including both their own reproduction (direct fitness) and helping relatives reproduce (indirect fitness) because relatives share some of the same genes.
Coefficient of Relatedness (r)
a number that shows how closely related two people are. It tells you the chance that you and another person share the same gene from a common ancestor.
direct fitness
gene transmitted via direct descent
Indirect Fitness
gene transmitted via relatives
Sahlins critique of kin selection theory
- hunter-gatherers haven’t invented fractions, how could they calculate coefficients of relatedness?
- adoption is arbitrary, not kinship related
critique 1 reveals fundamental misunderstanding of proximate and ultimate
Kin Recognition:
The ability to identify and differentiate between relatives and non-relatives
Kin selection theory
proposes differential behaviour toward relatives and non-relatives
Potential Kin Recognition Mechanisms:
Context-based discrimination –
Identifying kin based on location (e.g., family members usually live together).
Potential Kin Recognition Mechanisms:
Familiarity-based discrimination –
Recognizing kin through shared experiences, like growing up together.
Potential Kin Recognition Mechanisms:
Genetic-based discrimination –
Using biological cues, such as smell, to detect relatives.
Potential Kin Recognition Mechanisms:
Phenotype matching –
Comparing physical traits (e.g., facial features) to determine relatedness.
Westermarck Effect:
People who grow up together (especially before age 6) tend to have reduced sexual attraction or even aversion to each other. This may help prevent inbreeding. There is mixed evidence on whether facial cues play a role in this effect.
Theory of Mind (ToM):
The ability to understand that others have their own thoughts, intentions, and beliefs, which may be different from one’s own.
Group Selection
The idea that behaviors evolve for the good of the species.
Hamilton’s Rule:
rB>C
Hamilton’s Rule explains how natural selection favors behaviors that help relatives, based on the concept of inclusive fitness. It’s a formula used to predict when an organism will help a relative at a cost to itself.
Weaning conflict
is a natural disagreement between a mother and her infant over when to stop nursing.
