midterm Flashcards
Logical reasoning
- induction
- deduction
deduction
- ## a logical process in which the conclusion does not contain more info than the premises from which it’s based
deduction: Modus Ponens
P→ Q (conditional statement) - All birds have feathers
P (propositional stated) - Robins are birds
Q (conclusion deduced) - Robins have feathers.
deduction: Syllogism
P→ Q - If John is sick, then he will be absent.
Q → R - If John is absent, then he will miss his classwork.
P→ R - If John is sick, then he will miss his classwork
Deductive arguments are evaluated in terms of ….
their validity and soundness
validity
follows deductive logic
soundness
premises are true and the argument is valid
can you have a valid argument that isn’t sound? how about a sound argument that isn’t valid?
-you can have a valid argument that isn’t sound
P→ Q (conditional statement) - All birds have language
P (propositional stated) - Robins are birds
Q (conclusion deduced) - Robins have language
VALID BUT NOT SOUND
-but no way to have a sound argument that isn’t valid
-if it’s not valid and it’s not sound, it’s not a deduction-it’s a weak induction
Induction
a logical process in which the conclusion contas more info than the premises from which it’s based. It’s uncertain. Ex: John is a grandfather John is bald All grandfathers are bald
how are inductive arguments evaluated?
Inductive arguments are not evaluated for validity or soundness - they are strong or weak
theory
- an idea about how something in the world works-don’t need to test to have a theory-it’s a guess
- we don’t really know anything-it’s all theories
- real definition: a statement about the probable relationship between things in the world
- Scientific theories are testable and make falsifiable predictions (falsifiable=something you can test and prove wrong)
- theories are inductive, but must allow for deductive reasoning
The problem of induction
- can inductive arguments give us knowledge?
- there is no justification for generalizing from some number of observations, or an assumption that the world will always work the same in the future
hypothesis
a testable prediction deduced from a theory
the null hypothesis
- a general statement or default position that there is no relationship between 2 measured phenomena
- A null result falsifies the theory generated through inductive reasoning
statistical inference
- estimate properties of a population based on a sample
- inferring properties of population based on what happened in an experiment with a subgroup of that population
Karl Popper and falsification
- challenged the idea that findings confirmed a theory. Instead, Popper claimed that positive findings corroborated a theory, and tests should be designed to falsify theories
- If P, then Q; not P, therefore not Q
- Negative results require a revision of the theory
- doesn’t totally escape induction
- theories have more or less verisimilitude (i.e., degree of positive empirical support)
Problems: one must assume a null model. How is reality distributed? is it always normal?
Induction again!
-we assume a normal distribution-if falls within that, accept null
What are the alternatives to a null model?
- Have more sound apriori assumptions (bring in more realistic prior assumptions into the equation)
- Compare diff models
What are the alternatives?
- Have more sound apriori assumptions
- Compare diff models
What is the difference between induction and deduction?
Deduction: start with lots of info-funnel your way down to conclusion-only with info from top
Induction: all info follows logically from the statement above it-generalizing from a very specific point-conclusion has more info than premises
What do validity and soundness refer to?
- validity: has logical flow-the deductive format flows logically
- Soundness: has to do with accuracy-the premises being true
- for deductive arguments
How do you evaluate inductive arguments?
-by weak or strong
pretty subjective, so on exam will be pretty extreme ends of spectrum-very weak or very strong-so easy to tell
John is a guy/John is a brunette/all guys are brunette. What is this?
-An induction
Scientific theories must be ___ and _____
testable and falsifiable
What purpose does a null hypothesis serve?
-it’s better to prove things false time and time again to keep refining theory than to prove something true then let it go/not continue to test
What is verisimilitude?
How close your theory resembles reality-as you keep reworking it, your results are more and more mirroring reality
Theories can be ___, while hypotheses must be ____.
Inductive, deductive
Levels of explanation in the behavioral sciences
- For any trait, one can describe it at multiple levels
- proximate
- ultimate
- the proximate-ultimate distinction is a direct consequence of the theory of natural selection
- these interact-cultural mechanisms feed back into the genes and environment
- in order to fully understand a trait, need to understand both the ultimate and proximate mechanisms-they’re compatible-complementary-both important, though many social scientists are not interested in the ultimate explanation
ultimate explanation
we need to explain why these traits are present in the environment-why they have evolved
- species level events (not much of this-our genes don’t care about the species-evolution doesn’t try to save the species)
- the why
- concerned with the fitness consequences of a trait or behavior
- why is the trait favored by selection?
proximate explanation
- What are the mechanism by which those traits are implemented in the world?
- the how
- concerned with the mechanisms that underpin a trait or behavior
- behavior generators
proximate and ultimate explanations: why do we want ice cream?
- ultimate: Mechanism in our body that makes us want ice cream-because it tastes good-for centuries, sugar has been important to find in environment and difficult to find-behaviors to motivate you to find sugar and consume it
- not useful anymore, but leftover-used to be hard to find fats and sugars-not anymore-but still evolutionarily evolved
- proximate: doctors can explain how that works-taste buds-neurohormones-without even mentioning evolution
proximate and ultimate explanations: why do babies cry?
- proximate: includes both the external triggers of crying (e.g., physical separation from the caregiver, cold, or a lack of food) and internal mechanisms (the limbic system and the endogenous opioids involving the cessation of crying)
- has immediate causal triggers
- **as you can see, proximate explanations can sometimes seem like the why-but doesn’t actually explain why that trait exists for that species in the first place-just the apparent immediate cause (baby cries because cold)-so more the how of how that evolutionary function manifests itself, not the why
- ultimate: elicits care and defense from mothers and other caregivers
- appeals to the fitness benefits of the trait: infants that do not cry when in need of assistance are less likely to survive
proximate and ultimate explanations: why do male songbirds sing?
- proximate: increased daylight in the spring leads to increased testosterone production, which acts to activate a brain center than controls singing. Also, the role of experience in song-learning
- ultimate: singing functions to attract females and defend territory from other males
- enhances fitness
problems w proximate/ultimate distinctions reading
-designed to help clarify some errors the authors have noted in the literature in terms of how we think of proximate and ultimate-letter to social scientists
-but offers us a great learning opportunity to think about how to talk about different levels of analysis in these problems social scientists try to assess
-cooperative behavior: why are people cooperative? Why are we so nice to each other?
-some people say religion-that’s a proximate answer
-but why evolutionarily do we have that trait?
-linguistic structure and epigenetics-confusing, will not ask about on exam
-infant crying-already went over
-human reasoning-we engage in social exchange and so we’re particularly adept at IDing in a social exchange whether we’re getting a good benefit for the cost we paid-a lot of experiments revealed people good at reasoning tasks when frame them as being a cost and benefit-you need to think about why we’d be good at those reasoning problems-proximate: dedicated cognitive module for social exchange (there’s a part in our brain dedicated to reasoning), ultimate: need to pay attention to cost and benefit so not cheated in social exchange
-linguistic structure: lots of adaptive reasons why languages differ, and some cultural ones-but cultural transmission isn’t the reason for cling structure, why it varies (proximate)-we have it because there’s something about how our brains work that allow us to learn language-this has evolved evolutionarily (ultimate)
-why are misunderstandings of level of analysis common in the behavioral sciences
Proximate explanations are desired in the social sciences
The question of ultimate functionality is often not raised-don’t usually worry about evolutionary reason for why traits exist
Some terms have 2 different meanings: one at the ultimate level and another at the proximate level
E.g., cooperation, altruism, and spite are defined in terms of their net effects on inclusive fitness in biology (ultimate), but in psychology are often considered mental states (proximate)
Fitness: how many genes in your body are actually given on to next generation-how many of your genes make it to the next generation and the one after
Inclusive fitness: total count of your genes that are manifesting in the world-counting your offspring, and your family’s offspring (like siblings)
Altruism-just means nice to many, but to others about helping behavior for evolutionary purpose
Intentional language used in biology is an anthropomorphic shorthand for describing evolved strategies. But humans have conscious inventions that may or may not correspond to ultimate explanations.
Creates misunderstandings-people have conscious intentions that may or may not correspond to the ultimate explanation
We have a conscious narrative of why we’re doing something-moving towards goals we’ve set
Many things we do are unconscious
“Offspring are selected to demand more food than the parent wants to give” could be put more neutrally: “during the course of evolution selection acting on genetic differences in the begging behavior of offspring will have favored an increase in the intensity of begging, and this will have been favored to the extent that the level of begging by an individual offspring exceeds the optum level for the parent”
Marr’s 3 levels of analysis/Tri level of analysis
- David Marr-vision scientist-developed theoretical paradigm for levels of analysis describing psychological mechanisms
- can apply to any animal, trait, or piece of tech
- maps onto the ultimate proximate difference we’ve already described
1. computational
2. algorithmic
3. implementation
Marr’s 3 levels of analysis/Tri level of analysis: 1. computational
- what is the goal of the computation?
- Adaptive problem-what is this trait designed to do, through evolution? What is that thing for?
- Technological engineering
- Not saying how it works-just what is it designed to do?
Marr’s 3 levels of analysis/Tri level of analysis: 2. algorithmic
- what is the strategy of the computation? What is the mechanism?
- Information processing-you get some kind of info in some format-how does it actually get routed?
- Tells you exactly what is the processing strategy that tells you how something works
- The how-proximate explanation
Marr’s 3 levels of analysis/Tri level of analysis: 3. implementation
- How is it realized in physical material?
- Neurons, electronic circuitry, etc.
Human reasoning
- domain specificity
- dedicated systems to solve 1 domain, diff systems for another-dissociated from each other-so can be good at 1 thing and bad at another-smart in some areas but not others
- human reasoning is a domain specific activity
- proximate: there are specialized computational devices that allow people to detect cheaters in a social exchange
- ultimate: in social species w interessed cooperation, those who better defend against exploitation(i.e. cheating) will have better inclusive fitness
- 1 adaptive solution: cheater detection (?)
domain specificity
-good at one thing, but not another
human social reasoning for social exchange: Wason selection task
- tool used by psychologists to measure human reasoning ability
- the task had always shown a “content effect” but it was not understood
- there’s a rule, 4 cards, which do you have to turn over to see if rule is followed?
- p and not q
- but when the problem involves cost benefit structure-performance goes from about 4% correct to 74% correct
- testing if reasoning is sensitive to the content
human social reasoning for social exchange
- Wason selection task - tool used by psychologists to measure human reasoning ability
- the task had always shown a “content effect” but it was not understood
- there’s a rule, 4 cards, which do you have to turn over to see if rule is followed?
- p and not q
- but when the problem involves cost benefit structure-performance goes from about 4% correct to 74% correct
- testing if reasoning is sensitive to the content