Chapter 10: Development Over the Lifespan

Intro to Psychology

How did we get to where we are today?

Nurture vs. nature - it’s both!

  • Tabula rasa (blank slate) → extreme nurture perspective
  • Hard-wiring
    • Infants are startled by loud noises
    • Infants are surprised by physically improbable events (magic)
    • Infants can see (with very limited range)

Prenatal Development

  • At 4-8 weeks, male embryos’ rudimentary testes secrete testosterone. Otherwise, all embryos would be anatomically female.
  • Stressed mother → underweight babies with abnormal cortisol levels.
  • Father over 50 → higher risk of child with schizophrenia.
  • Teenage father → higher risk of premature babies or low birth weight.

The Infant’s World

  • Babies are born with motor reflexes, such as searching for something to suck on.
  • How to study babies:
    • Habituation: show something over and over until it becomes a habit, then change the stimulus and see whether the baby can tell.
    • Preferential looking: present two things and see which the baby looks at.

From Conception Through the First Year

  • Attachment: strong, intimate, long-lasting bond (often first one is the mother).
  • Separation anxiety: around 6-8 months, babies become wary or fearful of strangers.
  • Predictors of insecure attachment:
    • Abandonment and deprivation in the first year
    • Abusive/erratic parenting
    • Genetics
    • Stressful family circumstanceS (parent is ill, etc)


  • Attachment is a strong emotional connection to others.
    • It begins at birth (if not earlier).
    • Attachment is important because it motivates infants and parents to stay in close contact.
    • It occurs across species.
    • It’s not just about securing access to food.
    • Animals, humans included, have a need for emotional bond and comfort.
  • Imprinting: ducks attach to the first large moving thing that they see (usually mother duck).
  • Harlows’ Monkeys Experiment
    • Physical touch is important to social development.
    • Monkeys prefer cloth “mother” to wire “mother”.

Attachment style

  • Babies develop different models of bonding to others (and dealing with threats to bonds).
  • As long as family and life circumstances are consistent, attachment style is constant.
  • Tested with “Strange Situation”.
    • Child is brought in with caregiver, stranger enters, caregiver leaves.

Secure attachment

  • Infant plays while caregiver present
  • Departure of caregiver leads to distress, searching
  • Infant reacts positively to caregiver
  • Prefers caregiver to stranger

Insecure avoidant

  • Not upset when caregiver leaves
  • No preference for caregiver/stranger
  • Doesn’t seek comfort upon reunion

Insecure-ambivalent / insecure-anxious

  • Anxious even when caregiver present
  • Inconsolable even upon return
  • Seeks and resists contact with caregiver

Social Roles and Gender Roles

  • Social Roles: societal expectations regarding behavior or tendencies of a particular “type of person.”
  • Gender Roles: characteristics society associates with different genders.
    • Children pick up on these gender expectations as they grow up.
    • How much of later gender differences are due to nature vs. nurture?


  • Babies assimilate (gather) and accommodate (make updates in response to new experiences) information.

Piaget’s Stage Model

  • Sensorimotor Stage
    • Birth - 2 years
    • Month 1: all reflex
    • Months 2-4: accidents happen and get repeated
    • Months 4+: intentionally try to manipulate world
    • Year 2: trial and error
    • Takes until 15-18 months to differentiate self from others
    • Major skill: object permanence
  • Preoperational Stage
    • Ages 2-7
    • Abstract thought (fantasy play)
  • Concrete Operational Stage
    • Ages 7-12
    • Theory of Mind (put yourself in others’ perspective)
    • Actions are reversible
    • Focused on concrete, not abstract/hypothetical
  • Formal Operations
    • Ages 12+
    • Abstract thought
    • Logically test hypotheses instead of trial and error
    • Can do long-term planning

Criticisms of Piaget

  • Stage model assumes all children in stage are the same
  • Some argue Piaget underestimated kids’ cognitive abilities
    • Kids seem to have some object permanence very young


  • Children may have an innate mental module for language.
    • Deaf children invent sign languages that show similar sentence structures to actual languages.


  • Preconventional morality, not doing things for fear of punishment is seen in young children.
  • Conventional morality, based on conformity and approval of others as well as law, is seen around age 10+.
  • Postconventional morality, reasoned based on abstract principles and universal human rights, is seen in some adults.

Getting Children to be Good

  • Power assertion (physical punishment, taking things away, “because I said so”) are not effective and can backfire (child becomes angry and resentful).
  • Induction (appealing to child’s own empathy and sense of responsibility) is more effective.

Parenting styles

  • Authoritative
  • Authoritarian
  • Permissive
  • Uninvolved

The Physiology of Adolescence

  • Adrenarche: ages 6-12, children’s adrenal glands pump out hormones that affect brain development, particularly an androgen called DHEA.
    • Divert glucose to brain to mature brain regions important to interpreting social and emotional cues.
  • During puberty, synapses in the prefrontal cortex (impulse control and planning) are pruned.

Stages and Ages

  • Trust vs mistrust
  • Autonomy vs shame and doubt (young children learning to be autonomous without feeling too certain of their actions)
  • Initiative vs guilt
  • Competence vs inferiority (school age)
  • Identity vs role confusion (adolescence)
  • Intimacy vs isolation
  • Generativity vs stagnation (middle adulthood - do you sink into complacency and selfishness?)
  • Ego integrity vs dispair

Cognitive Aging

  • Cognitive deficits are observed in older individuals
    • Decreased working memory
    • Short-term memory declines more than long-term
  • Good health and socially active predict positive cognitive abilities
  • Some things improve:
    • Wisdom
    • Crystallized intelligence