MCAT Psych/Soc cheat sheet

Sensation is the detection of physical energy by sensory receptors; perception is the selection, organization, and interpretation of those signals.

Absolute threshold is the minimum stimulus intensity detected 50% of the time; difference threshold is the smallest reliably detected change, also called the just noticeable difference.

Weber's law states that the just noticeable difference is a constant fraction of the original stimulus intensity (ΔI/I = k), so stronger backgrounds require larger changes to be noticed.

Signal detection theory separates sensory sensitivity (d′) from response criterion; expectations, motivation, and payoffs shift the criterion and alter hits versus false alarms.

Sensory adaptation is decreased responsiveness to a constant stimulus; it frees attention for changing or novel stimuli.

Visual pathway: retina → optic nerve → optic chiasm → thalamus (lateral geniculate nucleus) → primary visual cortex; rods support low-light vision and cones support color and acuity.

Auditory transduction occurs in cochlear hair cells of the organ of Corti; place theory emphasizes the location of stimulation and frequency theory emphasizes firing rate.

Gate control theory holds that spinal cord gating and top-down brain signals modulate pain, so attention, emotion, and competing input can change perceived pain.

Gestalt principles such as proximity, similarity, continuity, closure, and figure-ground show that perception is organized by context and prior knowledge; cultural experience can also shape visual illusions and color categorization.

Classical conditioning pairs a neutral conditioned stimulus with an unconditioned stimulus until the conditioned stimulus alone elicits a conditioned response.

Acquisition strengthens a conditioned response; extinction weakens it when the unconditioned stimulus is withheld; spontaneous recovery is the return of an extinguished response after a delay.

Operant conditioning changes behavior through consequences: reinforcement increases behavior and punishment decreases behavior; positive means adding a stimulus and negative means removing one.

Reinforcement schedules: fixed-ratio and fixed-interval schedules produce pauses after reinforcement; variable-ratio and variable-interval schedules produce steadier responding, with variable ratio especially resistant to extinction.

Observational learning requires attention, retention, reproduction, and motivation; vicarious reinforcement occurs when seeing others rewarded increases imitation.

Social cognitive theory's reciprocal determinism holds that personal factors, behavior, and environment influence one another; self-efficacy predicts effort and persistence.

The health belief model states that behavior depends on perceived susceptibility, severity, benefits, barriers, cues to action, and self-efficacy.

Transtheoretical model stages are precontemplation, contemplation, preparation, action, and maintenance; relapse can return a person to an earlier stage.

Yerkes-Dodson law states that performance is best at moderate arousal for complex tasks and at higher arousal for simple tasks; learned helplessness follows uncontrollable aversive events.

Self-concept is the set of beliefs about one's attributes and roles; self-esteem is the evaluation of self-worth; self-efficacy is belief in capability for a specific task.

Social comparison uses reference groups to evaluate abilities and opinions; upward comparison compares with higher performers and downward comparison compares with lower performers.

Fundamental attribution error overattributes others' behavior to disposition and underestimates situational influence; actor-observer bias explains one's own behavior situationally.

Self-serving bias credits successes to internal factors and failures to external factors; it protects self-esteem but can distort attributions.

A stereotype is a cognitive generalization about a group; prejudice is an affective negative attitude; discrimination is unequal behavior toward a group.

Cognitive dissonance is discomfort from inconsistent cognitions; people reduce it by changing attitudes, adding consonant beliefs, or trivializing the inconsistency.

Central route persuasion relies on argument quality and high elaboration; peripheral route persuasion relies on cues such as attractiveness or message length and low elaboration.

Conformity increases with group unanimity and size; normative influence seeks approval and informational influence seeks correct interpretation; obedience is compliance with authority.

Group polarization makes group attitudes more extreme after discussion; groupthink suppresses dissent; bystander effect and diffusion of responsibility reduce helping in groups.

Social stratification is the hierarchical ranking of groups by access to wealth, power, prestige, and opportunity; systems include caste, estate, and class.

Socioeconomic status combines income, education, and occupational prestige; it predicts health, educational attainment, and access to political and material resources.

Social mobility can be vertical (up or down) or horizontal (lateral); intergenerational mobility compares parents and children, while intragenerational mobility tracks one lifetime.

Absolute poverty falls below a fixed survival minimum; relative poverty is judged against the standards of a particular society and limits social participation.

Marx emphasized class conflict between owners of production and workers; Weber added class, status, and party as separate dimensions of stratification.

Functionalism views stratification as necessary for filling important roles; conflict theory views it as reproduced by unequal power and institutional advantage.

Health disparities follow a socioeconomic gradient; low status and discrimination increase chronic stress and exposure to environmental hazards and reduce access to care.

Educational inequality is shaped by school funding, tracking, teacher quality, and stereotype threat; cultural capital affects navigation of educational institutions.

Intersectionality holds that overlapping identities such as race, class, gender, and immigration status create distinct advantages and disadvantages; social determinants of health include housing, income, and neighborhood conditions.