Chapter 3:

Developmental psychology: the study of progressive changes in behavior and abilities from conception to death.

Heredity ("nature"): transmission of physical and psychological characteristics from parents to offspring through the genes.

DNA: deoxyribonucleic acid, a molecular structure that contains coded genetic information.

Chromosomes: thread-like "colored bodies" in the nucleus of each cell that are made up of DNA.

Genes: specific areas on a strand of DNA that carry hereditary information.

Dominant gene: a gene whose influence will be expressed each time the gene is present.

Recessive gene: a gene whose influence will be expressed only when it is paired with a second recessive gene.

Polygenic characteristics: personal traits or physical properties that are influence by many genes working in combination.

Maturation: the physical growth and development of the body and nervous system.

Readiness: a condition that exists when maturation has advanced enough to allow the rapid acquisition of a particular skill.

Environment ("nurture"): the sum of all external conditions affecting development, including especially the effects of learning.

Congenital problems: problems or defects in the genes or by inherited characteristics.

Teratogen: radiation, a drug, or other substance capable of altering fetal development in nonheritable ways that cause birth defects.

Sensitive period: during development, a period of increased sensitivity to environmental influences. Also, a time during which certain events must take place for normal development to occur.

Deprivation: in development, the loss or withholding of normal stimulation, nutrition, comfort, love, and so forth; a condition of lacking.

Enrichment: in development, deliberately making an environment more stimulating, nutritional, comforting, loving, and so forth.

Reaction range: the limits environment places on the effects of heredity.

Temperament: the physical core of personality, including emotional and perceptual sensitivity, energy levels, typical mood, and so forth.

Developmental level: an individual's current state of physical, emotional, and intellectual development.

Neonate: newborn infant.

Cephalocaudal: from head to toe.

Proximodistal: from the center of the body to the extremities.

Social smile: smiling elicited by social stimuli, such as seeing a parent's face.

Social development: the development of self-awareness, attachment to parents or caregivers, and relationships with other children and adults.

Emotional attachment: an especially close emotional bond that infants form with their parents, caregivers, or others.

Surrogate mother: a substitute mother (often an inanimate dummy in animal research).

Contact comfort: a pleasant and reassuring feeling human and animal infants get from touching or clinging to something soft and warm, usually their mother.

Separation anxiety: distress displayed by infants when they are separated by their parents or principal caregivers.

Secure attachment: a stable and positive emotional bond.

Insecure-avoidant attachment: an anxious emotional bond marked by a tendency to avoid reunion with a parent or caregiver.

Insecure-ambivalent attachment: an anxious emotional bond marked by both a desire to be with a parent or caregiver and some resistance to being reunited.

Affectional needs: emotional needs for love and affection.

Parental styles: identifiable patterns of parental caretaking and interaction with children.

Authoritarian parents: parents who enforce rigid rules and demand strict obedience to authority.

Overly permissive parents: parents who give little guidance, allow too much freedom, or do not require the child to take responsibility.

Authoritative parents: parents who supply firm and consistent guidance combined with love and affection.

Maternal influences: the aggregate of all psychological effects mothers have on their children.

Paternal influences: the aggregate of all psychological effects fathers have on their children.

Biological predisposition: the presumed hereditary readiness of humans to learn certain ...