Research Methods

• Studies in developmental psychology are usually either cross-sectional or longitudinal.

• Cross-sectional research uses participants of different ages to compare how certain variables may change over the life span.

• Longitudinal research takes place over a long period of time.

  • Instead of sampling from various age groups as in cross-sectional research, a longitudinal study examines one group of participants over time.

Prenatal Influences on Development

Genetics

• Many developmental psychologists investigate how our genes influence our development.

• Specifically, researchers might look at identical twins in order to determine which traits are most influenced by genetic factors (e.g., the Bouchard twin study).

• Our genes also help determine what abilities we are born with, such as our reflexes and our process of developing motor skills.

Teratogens

• Certain chemicals or agents (called teratogens) can cause harm if ingested or contracted by the mother.

• Children of alcoholic mothers who drink heavily during pregnancy are at high risk for fetal alcohol syndrome (FAS).

Motor/Sensory Development

Reflexes

• All babies exhibit a set of specific reflexes, which are specific, inborn, automatic responses to certain specific stimuli.

• Rooting Reflex - When touched on the cheek, a baby will turn his or her head to the side where he or she felt the touch and seek to put the object into his or her mouth.

• Sucking reflex - When an object is placed into the baby’s mouth, the infant will suck on it. (The combination of the rooting and sucking reflexes obviously helps babies eat.)

• Grasping reflex - If an object is placed into a baby’s palm or foot pad, the baby will try to grasp the object with his or her fingers or toes.

• Moro reflex - When startled, a baby will fling his or her limbs out and then quickly retract them, making himself or herself as small as possible.

• Babinski reflex - When a baby’s foot is stroked, he or she will spread the toes.

The Newborn’s Senses

• Researchers know that babies can hear even before birth.

• Minutes after birth, a baby will try to turn his or her head toward the ­mother’s voice.

• Babies have the same basic preferences in taste and smell as we do.

• Babies love the taste of sugar and respond to a higher concentration of sugar in foods.

• Sight becomes our dominant sense as we age, but when we are born, hearing is the dominant sense due to babies’ poor vision.

• Babies are born almost legally blind.

• Babies like to look at faces and facelike objects (symmetrical objects and shapes organized in an imitation of a face) more than any other objects.

Motor Development

• Our motor control develops as neurons in our brain connect with one another and become myelinated.

• Research shows that most babies can roll over when they are about 5-1/2 months old, stand at about 8–9 months, and walk by themselves after about 15 months.

• These ages are very approximate and apply to babies all over the world.

• While environment and parental encouragement may have some effect on motor skills, the effect is slight.

Parenting

• Attachment Theory - Some species respond in very predictable ways to environmental stimuli: biologist Konrad Lorenz established that some infant animals (such as geese) become attached (“imprint”) on individuals or even objects they see during a critical period after birth.

Harry Harlow

• Harlow’s studies demonstrated the importance of physical comfort in the formation of attachment with parents.

• As Harlow’s infant monkeys developed, he noticed that the monkeys raised by the wire frame mothers became more stressed and frightened than monkeys raised with real mothers when put into new situations.

• The deprivation of an attachment with a real mother had long-term effects on these monkeys’ behavior.

Mary Ainsworth

• Mary Ainsworth researched the idea of attachment by placing human infants into novel situations.

• Ainsworth observed infants’ reactions when placed into a strange situation: their parents left them alone for a short period of time and then returned.

• Infants with secure attachments (about 66 percent of the participants) confidently explore the novel environment while the parents are present, are distressed when they leave, and come to the parents when they return.

• Infants with avoidant attachments (about 21 percent of the participants) may resist being held by the parents and will explore the novel environment.

  • They do not go to their parents for comfort when they return after an absence.

• Infants with anxious/ambivalent attachments (also called resistant attachments, about 12 percent of the participants) have ambivalent reactions to the parents.

  • They may show extreme stress when the parents leave but resist being comforted by them when they return.

Parenting Styles

• Developmental psychologist Diana Baumrind researched parent-child interactions and described three overall categories of parenting styles.

• Authoritarian parents set strict standards for their children’s behavior and apply punishments for violations of these rules.

• Permissive parents do not set clear guidelines for their children.

• Authoritative parents have set, consistent standards for their children’s behavior, but the standards are reasonable and explained.

Stage Theories

• Besides nature versus nurture, one of the other major controversies in developmental psychology is the argument about continuity versus discontinuity.

• Psychologist Lev Vygotsky’s concept of “zone of proximal development” is one answer to this question of continuity versus ­discontinuity: a child’s zone of proximal development is the range of tasks the child can perform independently and those tasks the child needs assistance with.

• Sigmund Freud and Erik Erikson, base their stages on psychoanalytic theories and are therefore less scientifically verifiable than the other stage theories.

  • They are included because their stages are still often used to describe how we develop in specific areas and are of historic importance.

Sigmund Freud

• Freud was the first to theorize that we pass though different stages in childhood.

• Freud said we develop through five psychosexual stages.

Oral stage

• In this stage, infants seek pleasure through their mouths.

• You might notice that babies tend to put everything they can grab into their mouths if they can get away with it.

• Freud thought that people fixated at this stage might overeat, smoke, and in general have a childlike dependence on things and people.

• Anal stage - This stage develops during toilet training.

  • If conflict around toilet training arises, a person might fixate in the stage and be overly controlling (retentive) or out of control (expulsive).

Phallic stage

• During this stage, babies realize their gender and this causes conflict in the family.

• Freud described the process boys go through in this stage as the Oedipus complex: a time when a boy resents his father’s relationship with his mother.

• The process for girls is called the Electra complex.

• Freud thought that conflict in this stage could cause later problems in relationships.

• Latency stage - After the phallic stage, Freud thought children go through a short latency stage, or period of calm, and between the ages of six and puberty of low psychosexual anxiety that most psychologists don’t regard as a separate stage.

Genital stage

• They then enter the genital stage where they remain for the rest of their lives.

• The focus of sexual pleasure is the genitals, and fixation in this stage is what Freud considers normal.

Erik Erikson

• Erik Erikson was a neo-Freudian, a theorist who believed in the basics of Freud’s theory but adapted it to fit his own observations.

• He thought that our personality was profoundly influenced by our experiences with others, so he created the psychosocial stage theory.

Trust versus mistrust

• Babies’ first social experience of the world centers on need fulfillment.

• Babies learn whether or not they can trust that the world provides for their needs.

• Erikson thought that babies need to learn that they can trust their caregivers and that their requests (crying, at first) are effective.

• This sense of trust or mistrust will carry throughout the rest of our lives, according to Erikson.

Autonomy versus shame and doubt

• In this next stage, toddlers begin to exert their will over their own bodies for the first time.

• Autonomy is our control over our own body, and Erikson thought that potty training was an early effort at gaining this control.

• Toddlers should also learn to control temper tantrums during this stage.

• Children’s most popular word during this stage might be “No!,” demonstrating their attempt to control themselves and others.

• If we learn how to control ourselves and our environment in reasonable ways, we develop a healthy will.

• Erikson believes we can then control our own body and emotional reactions during the rest of the social challenges we will face.

Initiative versus guilt

• In this stage, children’s favorite word changes from “No!” to “Why?” If we trust those around us and feel in control of our bodies, we feel a natural curiosity about our surroundings.

• Children in this stage want to understand the world.

• We take the initiative in problem solving and ask many (many!) questions.

• If this initiative is encouraged, we will feel comfortable about expressing our curiosity through the rest of the stages.

• If those around us scold us for our curiosity, we might learn to feel guilty about asking questions and avoid doing so in the future.

Industry versus inferiority

• This stage is the beginning of our formal education.

• Preschool inferiority and kindergarten were mostly about play and entertainment.

• In the first grade, for the first time we are asked to produce work that is evaluated.

• We expect to perform as well as our peers at games and school work.

• If we feel that we are as good at kickball (or math problems, or singing, and so on) as the child in the next desk, we feel competent.

• If we realize that we are behind or cannot do as well as our peers, having an inferiority complex, we may feel anxious about our performance in that area throughout the rest of the stages.

Identity versus role confusion

• In adolescence, Erikson felt our main social task is to discover what social identity we are most comfortable with.

• He thought that a person might naturally try out different roles before he or she found the one that best fit his or her internal sense of self.

• Adolescents try to fit into groups in order to feel confident in their identities.

• An adolescent should figure out a stable sense of self before moving on to the next stage or risk having an identity crisis later in life.

Intimacy versus isolation

• Young adults who established stable identities then must figure out how to balance their ties and efforts between work (including careers, school, or self-improvement) and relationships with other people.

• How much time should we spend on ourselves and how much time with our families? What is the difference between a platonic and a romantic relationship? Again, the patterns established in this stage will influence the effort spent on self and others in the future.

Generativity versus stagnation

• Erikson felt that by the time we reach this age, we are starting to look critically at our life path.

• We want to make sure that we are creating the type of life that we want for ourselves and our family.

• We might try to seize control of our lives at this point to ensure that things go as we plan.

• In this stage, we try to ensure that our lives are going the way we want them to go.

• If they are not, we may try to change our identities or control those around us to change our lives.

Integrity versus despair

• Toward the end of life, we look back at our accomplishments and decide if we are satisfied with them or not.

• Erikson thought that if we can see that our lives were meaningful, we can “step outside” the stress and pressures of society and offer wisdom and insight.

• If, however, we feel serious regret over how we lived our lives, we may fall into despair over lost opportunities.

Cognitive Development

Jean Piaget

• Jean Piaget was working for Alfred Binet, creator of the first intelligence test, when he started to notice interesting behaviors in the children he was interviewing.

• Piaget noted that children of roughly the same age almost always gave similar answers to some of the questions on the intelligence test, even if the answers were wrong.

• Normally, we incorporate our experiences into these existing schemata in a process called assimilation.

Sensorimotor Stage (Birth to Approximately Two Years Old)

• Babies start experiencing and exploring the world strictly through their senses.

• One of the major challenges of this stage is to develop object permanence.

  • Babies at first do not realize that objects continue to exist even when they are out of sensory range.

  • When babies start to look for or somehow acknowledge that objects do exist when they cannot see them, they have object permanence.

Preoperational Stage (Two to Approximately Seven Years Old)

• Acquiring the scheme of object permanence prepares a child to start to use symbols to represent real-world objects.

  • This ability is the beginning of language, the most important cognitive development of this stage.

• Children in this stage are also egocentric in their thinking, since they cannot look at the world from anyone’s perspective but their own.

• Concrete Operations (8 to Approximately 12 Years Old) - Piaget categorized children in the concrete-operations stage when they demonstrated knowledge of concepts of conservation, the realization that properties of objects remain the same even when their shapes change.

Formal Operations (12 Through Adulthood)

• This final stage of Piaget describes adult reasoning.

• Piaget theorized that not all of us reach formal operations in all areas of thought.

• Formal operational reasoning is abstract reasoning.

• We can manipulate objects and contrast ideas in our mind without physically seeing them or having real-world correlates.

Criticisms of Piaget: Information-Processing Model

• Many developmental psychologists still value Piaget’s insights about the order in which our cognitive skills develop, but most agree that he underestimated children.

• The information-processing model is a more continuous alternative to Piaget’s stage theory.

• Information processing points out that our abilities to memorize, interpret, and perceive gradually develop as we age rather than developing in distinct stages.

Moral Development

Lawrence Kohlberg

• Lawrence Kohlberg’s stage theory studied a completely different aspect of human development: morality.

• Kohlberg wanted to describe how our ability to reason about ethical situations changed over the course of our lives.

• Preconventional - Children in the preconventional level might say that Heinz should not steal the drug because he might get caught and put into prison.

• Conventional - Children in the conventional level might say that Heinz should steal the drug because then he could save his wife and people would think of him as a hero.

Postconventional

• A person evaluating a moral choice using postconventional reasoning examines the rights and values involved in the choice.

• Kohlberg described how self-defined ethical principles, such as a personal conviction to uphold justice, might be involved in the reasoning in this stage.

Criticisms of Kohlberg

• Some developmental psychologists challenge Kohlberg’s conclusions.

• One researcher, Carol Gilligan, pointed out that Kohlberg developed the model based on the responses of boys.

• Gilligan’s insights about Kohlberg’s theory demonstrate the importance of studying possible gender differences and how they might change as we develop.

  • However, recent research does not support Gilligan’s theory of gender differences in moral development.

Gender and Development

Biopsychological (Neuropsychological) Theory

• Biopsychological psychologists concentrate on the nature element in the nature/nurture combination that produces our gender role.

• One of the most significant findings is that, on average, female brains have larger corpus callosums than male brains.

Psychoanalytic Theory

• Freud thought that boys and girls develop their gender identities because they realize, unconsciously, that they can’t compete with their same-sex parent for the affections of the opposite sex parent.

• This is a compelling idea, and the Oedipus and Electra complex have been used in many movies and novels, but they are impossible to study experimentally.

Social-Cognitive Theory

• Social and cognitive psychologists concentrate on the effects society and our own thoughts about gender have on role development.

• Social psychologists look at how we react to boys and girls differently.

• Gender schema theory explains that we internalize messages about gender into cognitive rules about how each gender should behave.