psychology vocab module 14-16

behavior genetics

the study of the relative power and limits of genetic and environmental influences on behavior.

heredity

the genetic transfer of characteristics from parents to offspring.

environment

every nongenetic influence, from prenatal nutrition to the people and things around us.

chromosomes

threadlike structures made of DNA molecules that contain the genes.

DNA (deoxyribonucleic acid)

a complex molecule containing the genetic information that makes up the chromosomes.

genes

the biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins.

genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes.

identical (monozygotic) twins

develop from a single fertilized egg that splits in two, creating two genetically identical organisms.

fraternal (dizygotic) twins

develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment.

heritability

the proportion of variation among individuals in a group that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

interaction

the interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity).

molecular genetics

the subfield of biology that studies the molecular structure and function of genes.

molecular behavior genetics

the study of how the structure and function of genes interact with our environment to influence behavior.

epigenetics

"above" or "in addition to" (epi) genetics; the study of environmental influences on gene expression that occur without a DNA change.

evolutionary psychology

the study of the evolution of behavior and the mind, using principles of natural selection.

natural selection

the principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations.

mutation

a random error in gene replication that leads to a change.

social script

a culturally modeled guide for how to act in various situations.

sleep

a periodic, natural loss of consciousness — as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation. (Adapted from Dement, 1999.)

circadian [ser-KAY-dee-an] rhythm

our biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.

REM sleep

rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.

alpha waves

the relatively slow brain waves of a relaxed, awake state.

NREM sleep

non-rapid eye movement sleep; encompasses all sleep stages except for REM sleep.

hallucinations

false sensory experiences, such as seeing something in the absence of an external visual stimulus.

hypnagogic sensations

bizarre experiences, such as jerking or a feeling of falling or floating weightlessly, while transitioning to sleep.

delta waves

the large, slow brain waves associated with the deep sleep of NREM-3.

suprachiasmatic nucleus (SCN)

a pair of cell clusters in the hypothalamus that controls circadian rhythm. In response to light, the SCN causes the pineal gland to adjust melatonin production, thus modifying our feelings of sleepiness.