Chapter 1 Thinking Critically with Psychological Science

Chapter 1 Thinking Critically with Psychological Science

The Scientific Attitude

Scientific approach that is skeptical and open-minded
To shift away from illusions to reality, one must use Smart thinking or critical thinking: thinking that does not blindly accept things, but approaches with skepticism and examines the evidence carefully; Ask how did they know, on guts and instinct? Are the evidence biased?
However, must remember to have humility as too extreme would be stubbornness

The Limits of Intuition and Common Sense

Intuition often ends up nowhere
Tend to use a lot hindsight bias: tendency to believe that one would have known it after the results are shown; Seems like common sense. The answer was right there and look how obvious it was.
Experience it usually when looking back on history; eg. Glen Clark and the fast ferries
Humans tend to be overconfident, think we know more than we actually do (probably result of self-serving bias)
Hindsight causes us to be overconfident as we believe we would have picked the answer when the results are in front of us

The Scientific Method

Scientific theory: explanation using set of principles to organise/predict observations
No matter how good theory sounds, must put it to test
Must imply testable prediction = hypothesis
Beware of bias when testing
Good experiment can be replicated: the experiment can be repeated and would yield constant results; done with a different group of people or by a different person ending with constant results
Theory useful if:
(1) effectively organises range of observations
(2) implies clear predictions
Case study: research method where one person is studied in depth to find universal principles (things that apply to all)
Drawback is that the individual being studied could be atypical, results not universally contained
Survey: research method to get the self-reported attitudes/behaviours of people
Looks at cases less depth and wording of question affects the response given (framing)Tend to hang around group similar to us so using them as study is wrong
False consensus effect: tendency to overestimate other’s agreement with us; eg. Vegetarians believe larger amount of pop. is vegetarian than Meat-eaters
Population: all the cases in the group being studied
To make a good sample, use random sampling: sample that gives each case a good chance of being studied to ensure results within range
Naturalistic observation: observing and recording behaviour in natural settings with any control on situation
Like case study & survey, doesn’t explain behaviour
When finding a trait that accompanies another, not resulting effect, but correlation: the way 2 factors vary together and how well one predicts the other
Positive correlation: direct relationship where factors increase or decrease together
Negative correlation: inverse relationship where one factor goes up while one goes down
Does not explain cause, simply show relationship between factors
Illusory correlation: perceiving correlation when none exist; Notice random coincidences as not random, rather as correlated

Experiment

To isolate cause & effect, conduct experiments
Experimental condition: condition that exposes subjects to treatment
Control condition: condition that serves as a comparison to see effects of treatment on experimental condition subjects
Use random assignment: assigning subjects to experimental/control groups randomly to ensure no bias
Independent variable: experimental factor being manipulated and studied (by itself, alone, no need to depend on something) * x-axis
Dependent variable: experimental factor that depends on independent variable and changes in response to it * y-axis
Placebo: an inert substance/condition that maybe administered instead of a presumed active agent

Double-blind procedure: procedure in which the experimenter and the subject both don't know which treatment is given

Chapter 2 Neuroscience, Genetics, and Behaviors

Franz Gall developed the false theory called Phrenology – where bumps on the head dictate personality and intelligence. But the theory did direct our attention to brain region and function.
Psychologists that study these connections between biology and behavior are called Biological Psychologists.

Neural Communication

Our Neural System is basically made up of nerve cells or neurons. Each neuron is composed of Dendrites ~ message receiving fibers and Axons ~ message sending fibers which are insulated by the Myelin Sheath ~ fatty cells that help \speed up impulses.
Impulses or Action Potential is a brief electrical charge that travels down the axon as it becomes Depolarized due to the movement of positively charged ions entering the axon. After the transmission, the axon becomes Polarized as positive ions are pumped out during the Refractory Period.
The intensity of a stimulus is called the Threshold. A stimulus must exceed the threshold in order for a transmission to occur. The neuron will either fire or it won’t.Much like a gun, the neuron either fires or it doesn’t, there are no half-fires. This is called the all-or-none-response; if a stimulus is really strong, only the number of neurons firing will increase, not their speed.
The axon terminal of the sending neuron is separated from the receiving neuron by a tiny gap called the Synapse (or Synaptic Cleft). Once the action potential reaches the synapse, neurotransmitters, or chemical messengers, are released into the gap where it will bind onto specific receptor sites on the receiving neuron.
The most well know neurotransmitter is Acetylcholine(ACh), it causes muscles to contract in movement.
Endorphins are natural opiates produced in the body to control pain and induce pleasure. ("Morphine within")
Agonists are molecules which mimics the shape of natural neurotransmitters (Morphine)
Antagonists are molecules which block neurotransmitters from binding on receptor sites
The brain has a Blood-brain barrier which filters out unwanted chemicals in blood stream.

Neural and Hormonal Systems

The Nervous System is composed of the Central Nervous System (CNS) – brain and spinal cord, and Peripheral Nervous System (PNS) – links CNS to body’s muscles and glands by means of nerves which are bundles of sensory and Motor Neurons (they carry incoming and outgoing information respectively).
The Autonomic Nervous System (under PNS) has Sympathetic Nervous System – arouses the body for defense (increase heartbeat, dilating pupils, inhibit digestion etc.) and Parasympathetic Nervous System – calms the body after stress.
A simple Reflex is an automatic response to stimuli (like knee-jerk) involving messages from Sensory to Interneuron (Spinal Cord) to Motor Neuron.
The Endocrine System (slow hormone secreting system) communicates by releasing Hormones (chemical messengers) into the bloodstream.
In times of stress the ANS will signal Adrenal Glands (above kidney) to release epinephrine and norepinephrine hormones (also called adrenaline and noradrenaline.)
Pituitary gland is the most powerful endocrine gland, and under the influence of hypothalamus in brain, pituitary releases hormones that regulate glands and growth.

The Brain

Lesions– remove brain tissue
Electroencephalogram (EEG)– measures brain electric activity
Computed Tomograph (CT or CAT Scan) – taking x-ray photographs of brain
Positron emission tomograph (PET Scan) – detects radioactive glucose consumption in brain
Magnetic Resonance imaging (MRI) – generates brain images from magnetic activity
The brainstem – oldest portion in brain forms into the Medulla Oblongata – regulates involuntary processes like heartbeat and breathing.
Within the brainstem lies the reticular formation (looks like a finger-shaped net) which controls arousal, when you wake or sleep.
The Thalamus lies above brainstem and is shaped like two eggs. Its function is to act as a sensory switchboard relaying incoming signals to appropriate brain regions. But does not relay sensory signals dealing with smell.
The Cerebellum stores partial memory and learning capacities. But it mainly controls balance.
Limbic System includes Amygdala – influence emotions (fear, anger), and the Hippocampus – process memory . Removal of amygdala results in emotionless organisms upon arousal.
The Hypothalamus maintains body homeostasis (temperature, hunger, growth) and governs pituitary.
Glial cells guide and support nerve cells in the brain.
The brain is divided into 4 regions.
Frontal Lobe – behind forehead – has Motor Cortex (located at the back of frontal lobe, the cortex controls voluntary movement)
Parietal Lobe –top to back of head – has Sensory Cortex (located in the beginning of parietal lobe, the cortex processes \bodily senses)
Occipital Lobe –back of head – regulates vision.
Temporal Lobe –above ears – regulates hearing
¾ of the brain is uncommitted to motor or sensory functions. Theses brain regions are called Association Areas – areas involved in thinking, remembering, and speaking. The larger the association area, the more intelligent the species for they are able to anticipate future events.
The case with Phineas Gage showed researchers that damages in the frontal lobe could result in personality alterations because their normal "restraints" or inhibitions are erased. This was due to a tamping rod that shot from his left cheek and out his head, separating his internal motives and external judgement.
Stages of Language :
Visual Cortex – occipital lobe (back of head) – sees the visual stimulation (words)
Angular Gyrus – mid-side of parietal lobe – converts words into auditory code
Wernicke’s Area – between temporal and parietal lobe (side of head) - derives meaning from auditory code
Broca’s Area – mid-bottom of frontal lobe – controls motor cortex
Motor Cortex – back of frontal lobe – activates speech muscles to pronounce word
Damage to (1) cannot see, (2) cannot read, (3) cannot understand, (4) and (5) cannot speak.
Corpus Callosum joins the two hemispheres and is separated to cure epileptic seizures.
People with separated corpus callosums are referred to as Spilt-brain patients. They are unable to say what they see in their left visual field because speech is in left hemisphere and the hemispheres regulate opposite sides of body.
When split-brainers are asked to say what they saw, the left hemisphere will say what is seen in right visual field; when asked to point, get, or write what they saw, the right hemisphere will dictate what is seen in the left visual field.
Sign language is nevertheless language and is control by left hemisphere, if deaf people get a stroke in left hemisphere, signing will be disrupted.
Left Hemisphere : Mathematics, language, logical, reasoning. meaning
Right Hemisphere : Perceptual tasks, musical, artistic, emotion, face recognition, copying information.

Genetics and Behavior

Chromosomes contain Genes which are made up of DNA. There are 23 chromosomes in human egg and sperm; they are combined (fertilized) to make a 46 chromosome cell.
Evolutionary Psychologists study the effects of evolution of behavior of organisms.
Behavior Geneticists study genetic and environmental effects on behavior. – using Linkage Analysis.
Psychologists study Identical Twins (two babies within one egg) and Fraternal Twins (two babies in 2 separate eggs) to contrast adoption studies.
Identical twins have more similarities than fraternal twins.

Hertitability tell us what percentage of traits are because of genetic factors. Traits (height, intelligence, eye color etc.) are either due to genetic or environment there are no half-halves. If heritability of intelligence is 70%, that means 70% of the people will have inherited intelligence.

Chapters: 3-4 Genetics and Development

Prenatal Development and the Newborn

At 8 weeks after conception, babies are anatomically indistinguishable; 4/5th month different
Sex determined by 23rd pair of chromosome
X chromosome: comes from either mother or father; females have two, males have one
Y chromosome: comes from father, paired with x to form male
Y chromosome stimulates development of male sex organ by producing testosterone: most important male sex hormone, but females have it too
Gender: biologically or socially influenced characteristics which people define as male/female
zygotes: fertilized eggs; less than half survive pass 2 weeks
after 10 days, zygote attach to mother’s uterine wall and forms placenta for nourishment, zygote becomes embryo: developing human from 2 weeks to second month
after two months, looks human, called fetus: developing human from 2 months to birth
fetus hears muffled version of mother’s voice and prefers it after birth
harm can come when placenta gets teratogens: agents that can harm embryo/fetus during prenatal stage; a mother who is a heroin addict will have a heroin addicted baby
newborns are equipped with reflexes ideal to survival
rooting reflex: reflex, when touched on cheek, to open mouth and find nipple
perceptual abilities continue to develop during first month, can distinguish mother’s odour

Infancy and Childhood

maturation: biological growth processes that enable orderly change in behaviour, could be influenced by experiences
maturation sets the basic course of development and experience adjust it
lack of neuron connections reason why earliest memories rarely earlier than third birthday (experiences help develop neural connections)
Rosenzweig and Krech reared some young rats in solitary confinement and others in playground; found those in playground develop thicker and heavier brain cortex
For optimum development, early years critical –use it or lose it; but development exists through life as neural tissues changes –experiences nurture nature

plasticity: brain ability to reoganize pathways to compensate damage; if laser damaged spot in cat’s eye, brain area receiving input from spot will start responding to stimulation from nearby areas in eye; brain hardware changes with time –can rewired with new synapses
children brains most "plastic" –surplus of neurons
when neurons are destroyed, nearby ones may partly compensate by making new connections
experience influences motor behaviour
experience(nurture) before biological development(nature) has limited effect

Cognitive Development

Cognition: mental activities associated with knowing, thinking, & remembering
Piaget believed child’s mind develops through series of stages
Piaget believed children built schemas: concept or framework that organises and interprets info; mental molds into which we pour our experience
assimilation: interpreting new experience in terms of existing schemas; given schema for dog, child may call 4-legged animals doggies
to fit new experiences, we accommodate: adapting one’s schemas to incorporate new info; child realises doggies schemas too broad and refines category

Piaget’s 4 stages of Cognitive Development

Sensorimotor Stage (Birth – 2 years old)
Infants know world in terms of sensory impressions and motor activities
Lack objective permanence: awareness that things continue to exist when not perceived; Baby believes toy only exists when it is starring at it
Preoperational Stage (preschool – 6/7 years old)
Child learns to use language, but aren’t able to comprehend mental operations of concrete logic; lacks conservation: principle that quantity remains the same despite changes in shape; water from tall, thin glass poured into wide, flat glass would be the same
Children are egocentric: inability to see another’s point of view
Concrete Operational Stage (6/7 – 11 years old)
Children gain mental operations that enable logical thinking about concrete events; understands conservation and mathematical transformation (reversing arithmetic operations)
Formal Operational Stage (12 years -life)
Reasoning expands from concrete (involving actual experiences) to abstract thinking (involving imagined realities and symbols)
Children able to solve hypothetical situations and its consequences

researchers believe development more continuous than did Piaget

Social Development

infants develop intense bond with those who care for them; prefers familiar faces and voices
after object permanence, develop stranger anxiety: fear of strangers commonly displayed after 8 months of age
attachment: emotional tie with another person; shown by child seeking closeness to caregiver (those who are comfortable, familiar, and responsive to needs) and distress when seperated
psychologists use to believe attachment through need for nourishment, but now consider wrong
Harlow’s Monkey Studies: Harry Harlow bred monkeys of which he separates from mothers shortly after birth; in cages were a cheesecloth baby blanket; baby monkeys formed intense attachment to blanket –distressed when taken away; later, Harlow created 2 artificial mothers ("Harlow’s Mothers"), one bare wire cylinder with wooden head, other a cylinder wrapped with terry cloth; when reared with nourishing wire mother and nonnourishing cloth mother, monkeys preferred cloth mother; concluded body contact more important than nourishment
Critical period: an optimal period shortly after birth when organism’s exposure to certain stimuli/experience produces proper development; first moving object a duckling sees is mother, then follows only it
Developmental psychologists believe humans don’t have precise critical period
Imprinting: process by which certain animals form attachment during critical period; humans don’t imprint, but becomes attached to "known"
Temperament: person’s characteristic emotional reactivity and intensity; temperaments endure; ex. easy-going, quiet, placid
Heredity predispose human differences; anxious infants have high heart rates and reactive nervous system; identical twins more likely to have similar temperaments than nonidentical
Sensitive, responsive mothers have infants who are securely attached while the opposite (attend only when felt like doing and ignores at other times) have infants who are insecurely attached
Anxiety over separation from parents peak at 13 months and gradually declines after
Erik Erikson claims securely attached children approach life with sense of basic trust: sense that the world is predictable and trustworthy
Deprivation of attachment causes withdraw, fear, and other negative consequences; most abusive parents have been neglected/battered as children
Many developmentalists believe quality infant day care doesn’t hinder secure attachement
Divorces place children at increased risk for developing social, psychological, behavioral, and academic problems
By age 12, most children develop self concept: sense of one’s identity and personal worth
Children’s views of themselves affect actions; positive self-concept produces confidence, independence, optimism

Child-Rearing Practices