⚖️ Confusing Pairs Study Guide

These get confused because both involve "randomness" in a study's design, but they happen at different stages. Random sampling is about who gets chosen to participate at all, pulled from the wider population before the study even starts. Random assignment is about where they go once they're already in the study, sorting existing participants into groups. Quick tip: sampling comes first (population → study), assignment comes second (study → groups).

The confusion usually comes from not realizing that "quantitative" and "qualitative" describe the type of data, not the quality of the research. Quantitative data is anything you can put a number on — height, reaction time, test scores. Qualitative data is descriptive and non-numeric — color, mood, an open-ended interview response. Quick tip: quantitative = quantity (numbers); qualitative = qualities (descriptions).

Students often assume "control" means the group researchers have more control over, but it actually refers to what that group receives. The experimental group gets the treatment being tested; the control group gets nothing, or a placebo, so researchers have a baseline for comparison. Quick tip: without the control group, you have nothing to compare your results against — it "controls" for outside factors.

This pair trips people up because both variables are part of the same experiment, so it's easy to blur which one the researcher is actually changing. The independent variable is what the researcher manipulates; the dependent variable is what gets measured as a result. Quick tip: the dependent variable "depends" on the independent variable — it's the outcome, not the cause.

These sound like synonyms in everyday speech, but in research methods they measure two different things. Reliability is about consistency — would you get the same result if you measured again? Validity is about accuracy — are you actually measuring what you claim to be measuring? A bathroom scale that's off by 10 lbs but gives the same wrong number every time is reliable but not valid. Quick tip: reliability = repeatable, validity = right.

Both are ways of studying change over time, so students mix up which one actually follows the same people. A cross-sectional study compares different age groups all at once, at a single point in time. A longitudinal study follows one group of people repeatedly, over years or even decades. Quick tip: longitudinal takes the "long" road — one group, tracked over a long stretch of time.

Both show up together on correlation questions, which makes them feel like the same statistic when they're actually answering different questions. The correlation coefficient (r-value) describes the strength and direction of a relationship between two variables. Statistical significance (p-value) tells you how likely it is that relationship happened by chance rather than reflecting a real effect. Quick tip: r-value asks "how strong?", p-value asks "how likely is this real?"

This is easy to mix up with random assignment because the wording is nearly identical, but random selection is really just another name for random sampling — choosing who's included in the study out of the broader population. Random assignment happens after that, sorting the people already selected into experimental or control groups. Quick tip: selection picks who's in the study; assignment decides which group they land in.

The confusion is usually about which direction the tail is actually pointing, since "positive" and "negative" don't refer to good or bad here. A positive skew has its tail stretching toward the higher (positive/right) values, pulling the mean up above the median. A negative skew has its tail stretching toward the lower (negative/left) values, pulling the mean down below the median. Quick tip: the skew is named for the direction of the tail, not where most of the data sits.

Both are branches of the peripheral nervous system, which makes them easy to lump together as "the same thing." The somatic nervous system controls voluntary movement — the muscles you consciously choose to move. The autonomic nervous system controls involuntary processes — heart rate, digestion, breathing — that run automatically without you thinking about them. Quick tip: somatic = "so, I'm moving on purpose"; autonomic runs on auto-pilot.

Both are subdivisions of the autonomic nervous system, which is exactly why students remember "autonomic" and forget which branch does what. The sympathetic system revs you up for fight-or-flight — heart rate up, digestion pauses. The parasympathetic system calms you back down — rest-and-digest, heart rate drops. Quick tip: parasympathetic sounds soft — think "paradise," resting on a beach.

Both are chemical messengers, so the overlap in function makes them feel interchangeable. Neurotransmitters carry messages across the tiny gap between neurons, within the nervous system. Hormones travel through the bloodstream instead, released by the endocrine system, and tend to act more slowly and broadly across the whole body. Quick tip: neurotransmitters transmit locally between neurons; hormones ride the bloodstream.

The Greek-sounding roots don't offer much of a hint, so students often guess at which one helps and which one blocks. Agonists are chemicals that aid or mimic a neurotransmitter's effect. Antagonists are chemicals that block or work against a neurotransmitter's effect. Quick tip: an antagonist is "against" the neurotransmitter — think of an antagonist in a story working against the hero.

Both areas are damaged in different types of aphasia, so their functions blend together in memory. Broca's area handles physical speech production — damage here means halting, effortful speech. Wernicke's area handles speech comprehension — damage here means fluent but meaningless speech. Quick tip: Broca's = broken speech (production); Wernicke's = words don't make sense (comprehension).

Both terms describe twins, so it's easy to forget which prefix means "same" and which means "different." Monozygotic twins come from a single fertilized egg that splits — genetically identical. Dizygotic twins come from two separate eggs fertilized separately — genetically no more similar than regular siblings. Quick tip: mono = one egg (identical); di = two eggs (fraternal).

All three are types of neurons, so the direction each one carries information is the detail that actually distinguishes them. Sensory neurons carry information from the senses and body up to the brain. Motor neurons carry commands from the brain back out to the body. Interneurons sit in between, in the spinal cord and brain, connecting the two and enabling quick reflexes. Quick tip: sensory in, motor out, inter in the middle.

Both are parts of a neuron, so remembering which end does the receiving and which does the sending takes a deliberate mental hook. Dendrites receive incoming signals from other neurons. The axon sends the signal onward, away from the cell body. Quick tip: dendrites detect (receive); axon exits (sends).

Both are photoreceptors in the retina, so their names alone don't hint at what each one specializes in. Rods handle night and peripheral vision, only seeing in black, white, and shades of gray. Cones handle daytime, detailed, and color vision. Quick tip: rods = rough vision in the dark; cones = color in daylight.

Both are thresholds related to detecting stimuli, so it's easy to blur what exactly is being detected. Absolute threshold is the minimum stimulation needed to notice a stimulus at all, at least half the time. Difference threshold is the minimum amount a stimulus has to change before you notice the change. Quick tip: absolute threshold detects something; difference threshold detects a change in something already there.

Both senses deal with the body's physical position, which makes them feel like the same sense described twice. Kinesthetic sense tracks the position and movement of individual body parts, like knowing where your arm is without looking. Vestibular sense tracks overall balance and head movement, using structures in the inner ear. Quick tip: kinesthetic = individual body parts; vestibular = overall balance.

Both theories try to explain how humans perceive color, which makes it tempting to treat them as competing rather than complementary. Trichromatic theory says color vision comes from three types of cone receptors (red, green, blue). Opponent-process theory says color is processed in three opposing pairs (red-green, blue-yellow, white-black), which explains afterimages. Quick tip: trichromatic explains the receptors; opponent-process explains what happens after, in the brain.

Both are processes involved in how we experience sensation, so it's easy to conflate "converting" a stimulus with "getting used to" one. Transduction is converting raw physical energy (light, sound) into a neural signal the brain can use. Sensory adaptation is the brain tuning out a constant, unchanging stimulus over time, like no longer noticing a scent after a few minutes. Quick tip: transduction is the conversion step; adaptation is getting used to something already converted.

Both are types of depth cues, so students often can't recall which one needs two eyes and which works with just one. Binocular cues require both eyes working together to judge depth. Monocular cues work with just a single eye. Quick tip: binocular = two eyes; monocular = one eye.

Both are sleep disorders, so the specific mechanism behind each one is the detail that actually separates them on an exam. Insomnia is difficulty falling or staying asleep. Sleep apnea is a physical disorder where breathing repeatedly stops during sleep. Quick tip: insomnia is about can't sleep; apnea is about can't breathe while asleep.

These are pure spelling look-alikes, sharing most of their letters, which is really the entire source of confusion. Consciousness is your awareness of your immediate surroundings and internal state. Conscientiousness is a Big Five personality trait describing dependability, organization, and follow-through. Quick tip: consciousness is about awareness; conscientiousness is about being careful and responsible — notice the extra "enti" in the middle.

Both are hormones that regulate hunger, working in opposite directions, which is exactly what makes them easy to swap. Leptin signals the brain that the body has enough energy stored, reducing appetite. Ghrelin signals the brain that it's time to eat, increasing appetite. Quick tip: leptin makes you feel less hungry (think "let up" on eating); ghrelin makes your stomach growl.

Both describe physical properties of sound waves, so it's easy to forget which one controls pitch and which one controls loudness. Wavelength determines pitch — long wavelengths sound low, short wavelengths sound high. Amplitude determines loudness — tall waves are loud, short waves are soft. Quick tip: wavelength = pitch (long/low, short/high); amplitude = volume (tall/loud, short/soft).

This is the visual-light version of the sound-wave pair above, so the two easily get merged into one concept covering "waves" in general. Wavelength determines hue (color) — red has a long wavelength, blue/violet a short one. Amplitude determines brightness — a taller wave looks brighter. Quick tip: same rule as sound — wavelength decides which quality (color/pitch), amplitude decides how much (bright/loud).

Both are refractive vision problems, and the "near" and "far" in their common names get mixed up under exam pressure. Myopia (nearsightedness) happens when the eye is too long, so light focuses in front of the retina, blurring distant objects. Hyperopia (farsightedness) happens when the eye is too short, so light focuses behind the retina, blurring close objects. Quick tip: myopia — the "o" looks like a close-up zero, blurry far away; hyperopia lets you see far.

Both are neurological/autoimmune conditions that impair movement, so the specific mechanism is what separates them on a question. Multiple sclerosis destroys the myelin sheath insulating neurons, impacting the central nervous system. Myasthenia gravis blocks acetylcholine at the junction between nerve and muscle, impacting the peripheral nervous system. Quick tip: MS attacks the insulation (myelin) in the CNS; MG blocks the chemical signal (acetylcholine) in the PNS.

Both are forms of color blindness, so the number of working cone types — the actual distinguishing detail — is easy to overlook. Dichromatism means only two of the three cone types work, causing difficulty distinguishing certain colors. Monochromatism means only one (or zero) cone types work, causing vision in shades of gray only. Quick tip: di = two cones working; mono = one (or none), full grayscale.

Both describe senses interacting in unusual ways, so it's tempting to treat one as just a stronger version of the other. Sensory interaction is senses working together normally to shape perception, like smell affecting taste. Synesthesia is a rarer neurological condition where stimulating one sense involuntarily triggers a completely different, unrelated sense, like seeing colors when hearing music. Quick tip: sensory interaction is normal teamwork between senses; synesthesia is an atypical crossover.

Both are part of Piaget's theory of how schemas change, so it's easy to blur which direction the adjustment goes. Assimilation is fitting new information into an existing schema without changing the schema itself. Accommodation is changing or creating a schema because the new information doesn't fit the old one. Quick tip: assimilation absorbs into what's already there; accommodation alters what's already there.

Both describe directions information can flow during perception, so the "up" and "down" are what actually need to stick. Bottom-up processing starts with raw sensory details and builds up to the big picture. Top-down processing starts with expectations or existing knowledge and uses that to interpret the details. Quick tip: bottom-up builds from the ground (senses) up; top-down starts from the brain's expectations and works down.

Both effects describe which items from a list get remembered best, so "first" and "last" are the whole ballgame here. The primacy effect is better recall for items at the beginning of a list. The recency effect is better recall for items at the end of a list. Quick tip: primacy = prime position, first; recency = most recent, last.

Both are types of long-term memory, so the kind of knowledge each one stores is the actual distinguishing feature. Implicit (nondeclarative) memory covers skills and habits you don't consciously think about, like riding a bike. Explicit (declarative) memory covers facts and events you can consciously state. Quick tip: you can explicitly explain explicit memories; implicit memories are more "just do it."

Both are types of amnesia, so the direction of the memory loss — forward or backward in time — is what actually distinguishes them. Anterograde amnesia means the person can't form new memories going forward. Retrograde amnesia means the person can't recall memories from before the injury. Quick tip: anterograde = after the injury, can't make new ones; retrograde = memory goes "backward," lost old ones.

Both are problem-solving strategies, so which one guarantees a correct answer and which one just estimates is the key distinction. Algorithms are step-by-step methods that are slower but guaranteed to produce a correct solution. Heuristics are mental shortcuts, or "rules of thumb," that are faster but not always accurate. Quick tip: algorithm = a formula that always works; heuristic = a guess that usually works.

The confusion here is that both are ways of retrieving memory, so it's easy to blur them into one concept. The real difference is whether you're given a cue. Recall means pulling information from memory with no options in front of you — a short-answer or essay question. Recognition means picking the right answer out of choices already shown to you — multiple choice. Quick tip: recognition gives you options to recognize; recall leaves you with a blank page.

Both are heuristics (mental shortcuts) that lead to biased judgments, so what each one is actually basing the shortcut on is the real distinction. The representativeness heuristic judges likelihood based on how closely something matches a stereotype or prototype. The availability heuristic judges likelihood based on how easily examples come to mind. Quick tip: representative = does it "look the part"?; availability = what's "available" in memory right now?

Both are types of standardized tests, so what each one is actually trying to predict or measure is the key difference. Achievement tests measure what you've already learned. Aptitude tests measure your potential to learn or perform in the future. Quick tip: achievement looks backward at what you've achieved; aptitude looks forward at your potential.

Both are types of intelligence in the fluid/crystallized model, so which one relies on raw reasoning versus accumulated knowledge is the key detail. Fluid intelligence is the ability to reason and solve novel problems on the spot, largely independent of prior knowledge. Crystallized intelligence is accumulated knowledge and skills built up through life experience, which tends to hold steady or grow with age. Quick tip: fluid = flexible, in-the-moment reasoning; crystallized = knowledge that's "set" from experience.

Both describe getting stuck in a rigid way of thinking, so the specific type of "stuck" is what needs to stay clear. Mental set is continuing to use a strategy that worked before, even when it no longer fits the new problem. Functional fixedness is only being able to see an object's traditional use, missing other possible functions. Quick tip: mental set is stuck on a method; functional fixedness is stuck on an object's normal use.

Both describe directions of thinking during problem-solving, so "narrowing" versus "expanding" is the whole distinction. Convergent thinking narrows down multiple possibilities to find the single best answer. Divergent thinking expands outward, generating many possible solutions or ideas. Quick tip: convergent thinking converges (narrows) toward one answer; divergent thinking diverges (spreads) into many.

Both are subtypes of long-term memory, so what kind of content each one stores is the real distinguishing detail. Episodic memory stores personal experiences and events from your own life. Semantic memory stores general facts and learned knowledge about the world, independent of when or where you learned it. Quick tip: episodic = episodes from your own life; semantic = general facts, like a dictionary.

Both are types of interference that disrupt memory, so which direction the disruption flows — old blocking new, or new blocking old — is the key detail. Proactive interference is old information getting in the way of learning new information. Retroactive interference is newly learned information disrupting recall of older information. Quick tip: proactive pushes forward, old blocking new; retroactive reaches backward, new blocking old.

Both describe failing to notice something visually, so what exactly goes unnoticed is the detail that separates them. Inattentional blindness is failing to notice something new that appears, because attention is focused elsewhere. Change blindness is failing to notice a change to something already in the scene. Quick tip: inattentional blindness misses something new; change blindness misses a change to what's already there.

Both are reasoning errors involving past events influencing present decisions, so the type of past-focused thinking is the key difference. The gambler's fallacy is believing a random event's outcome is influenced by previous outcomes (a coin is "due" for heads). The sunk-cost fallacy is continuing to invest in something because of what's already been invested, even when it's not paying off. Quick tip: gambler's fallacy misjudges odds; sunk-cost fallacy misjudges past investment.

All three describe mental shortcuts for organizing information, so which one is the "container," the "best example," and the "expectation" is what needs to stay distinct. A schema is the overall mental framework for organizing information about a concept. A prototype is the single best or most typical example within that schema. A perceptual set is an expectation, built from schemas, that shapes how you interpret new sensory information. Quick tip: schema = the whole file folder; prototype = the best example inside it; perceptual set = expecting to see that example before you even look.

Both are forms of learning, so it's easy to lose track of which one involves a choice and which one doesn't. Classical conditioning is involuntary learning, where a neutral stimulus becomes linked to an automatic response. Operant conditioning is voluntary learning, where behavior is shaped by its consequences (reinforcement or punishment). Quick tip: classical = involuntary, reflexive; operant = voluntary, consequence-driven.

Both are units of language, so which one is about sound and which is about meaning is the actual distinction. Phonemes are the smallest units of sound in a language. Morphemes are the smallest units of meaning in a language, like a root word or a prefix. Quick tip: phoneme sounds like "phone" — think sound; morpheme carries meaning.

Students often assume "negative" means "bad," so both sound like punishment — that's the trap. "Negative" here just means taking something away, and what matters is whether the behavior increases or decreases afterward. Negative reinforcement removes something unpleasant to strengthen a behavior (fastening your seatbelt to stop the annoying beeping). Negative punishment removes something desirable to weaken a behavior (losing phone privileges). Quick tip: reinforcement always increases behavior, punishment always decreases it — "negative" only ever describes the removal, never the outcome.

Both describe how conditioned responses spread (or don't) to similar stimuli, so which direction that spread goes is the key detail. Generalization is responding the same way to stimuli that are merely similar to the original conditioned stimulus. Discrimination is learning to respond only to the exact original stimulus, not similar ones. Quick tip: generalization broadens the response; discrimination narrows it back down.

Same trap as negative reinforcement/punishment, but flipped: "positive" doesn't mean good here, it means adding something. Positive reinforcement adds something desirable to strengthen a behavior. Positive punishment adds something undesirable to weaken a behavior. Quick tip: positive = something is added; whether it's reinforcement or punishment still depends on if the behavior goes up or down.

Both parenting styles sound similar because of the shared "author-" root, so the amount of flexibility involved is what actually separates them. Authoritarian parenting is strict, rule-based, and low on give-and-take ("my way or the highway"). Authoritative parenting is a balanced style, with clear expectations but also warmth and negotiation. Quick tip: authoritarian is rigid, like a dictatorian; authoritative still has authority, but balanced with warmth.

Both are early stages in Piaget's theory of cognitive development, so which milestone belongs to which stage takes some sorting out. The sensorimotor stage (birth to about 2) is defined by exploring the world through senses and motor actions, before object permanence develops. The preoperational stage (about 2 to 6-7) is defined by pretend play and language, but still lacking logical operations like conservation. Quick tip: sensorimotor = senses and motor skills first; preoperational comes next, but before ("pre-") logical operations.

Both describe where someone believes control over their life comes from, so "internal" and "external" are easy to swap under pressure. Internal locus of control is the belief that you control your own outcomes. External locus of control is the belief that outside forces (luck, other people, fate) control your outcomes. Quick tip: internal = control comes from inside you; external = control comes from outside forces.

Both describe why someone does something, so the source of the motivation — internal satisfaction versus outside reward — is the key distinction. Intrinsic motivation is doing something for the internal, personal satisfaction of it. Extrinsic motivation is doing something to earn an external reward or avoid punishment. Quick tip: intrinsic comes from inside; extrinsic comes from an external reward.

Both describe cultural values, so which one prioritizes the group and which prioritizes the person is the actual distinction. Collectivist cultures emphasize family, community, and group harmony over individual needs. Individualistic cultures emphasize personal uniqueness, independence, and individual achievement. Quick tip: collectivist = the collective (group) comes first; individualistic = the individual comes first.

Both are persuasion techniques that use a two-step request, so the order of the steps — small-then-big or big-then-small — is what actually separates them. Foot-in-the-door starts with a small request to gain agreement, then follows with a bigger one. Door-in-the-face starts with a large request expected to be refused, then follows with a smaller, more reasonable one. Quick tip: foot-in-the-door starts small and builds up; door-in-the-face starts big, then backs down.

Both are biases about how we explain behavior, so whose behavior is being judged — someone else's or your own — is the key detail. The fundamental attribution error is blaming someone else's disposition (personality) while overlooking the situation they were in. Actor-observer bias goes a step further: blaming other people's disposition, but blaming your own behavior on the situation instead. Quick tip: fundamental attribution error is about judging others; actor-observer bias adds the flip side — judging yourself differently than you judge others.

All three "self" terms sound interchangeable, so which one is about worth, which is about confidence, and which is about identity is the real distinction. Self-esteem is your overall sense of self-worth. Self-efficacy is your confidence in your ability to perform a specific task or skill. Self-concept is your broader description and evaluation of who you are as a person. Quick tip: self-esteem = how much you value yourself; self-efficacy = how capable you feel at a task; self-concept = your overall sense of identity.

Both describe why people conform, so the split feels arbitrary until you ask what's motivating the conformity. Normative influence is about wanting to be liked or avoid standing out — you go along even if you privately disagree. Informational influence is about wanting to be right — you go along because you genuinely believe others have better information than you. Quick tip: normative = fitting in, informational = figuring it out.

Both are routes to persuasion in the Elaboration Likelihood Model, so which one focuses on the message and which focuses on surface cues is the key distinction. Peripheral route persuasion is influenced by incidental cues, like the attractiveness or credibility of the speaker, rather than the argument itself. Central route persuasion is influenced by the actual facts, logic, and quality of the argument. Quick tip: central route sticks to the center of the argument (the facts); peripheral route is swayed by things on the edges (looks, delivery).

All three describe how the presence of others affects performance, so whether performance goes up, down, or the effort itself just drops is what separates them. Social facilitation is improved performance on simple, well-learned tasks when others are watching. Social inhibition is the opposite: worse performance on those same simple tasks around others. Social loafing is exerting less individual effort specifically in a group setting. Quick tip: facilitation and inhibition are about performance going up or down while being watched; loafing is about effort dropping while working with others.

Both describe going along with others, so the presence (or absence) of a direct order is the key distinction. Conformity is adjusting your own behavior or beliefs to match a group, with no direct order involved. Obedience is complying specifically with a command or order from an authority figure. Quick tip: conformity is peer pressure; obedience is following orders.

Both describe how group discussion can distort decision-making, so whether opinions get stronger or a group avoids realistic options entirely is the key difference. Group polarization is a group's existing opinions becoming more extreme after discussing them together. Groupthink is a group prioritizing harmony and agreement so much that it overrides realistic, critical thinking. Quick tip: polarization pushes opinions further; groupthink suppresses disagreement altogether.

Both are motivation theories, so which one is about restoring balance and which is about seeking excitement is the key distinction. Drive reduction theory says we're motivated to reduce internal tension and return the body to homeostasis (like eating when hungry). Arousal theory says we're motivated to seek out an optimal level of stimulation, sometimes increasing arousal rather than reducing it (like riding a rollercoaster). Quick tip: drive reduction seeks less tension; arousal theory seeks the right amount of stimulation, which can mean seeking more.

Both are Freudian defense mechanisms that redirect negative energy, so where that energy actually ends up is the key distinction. Displacement redirects negative feelings toward a safer, unrelated target (yelling at a sibling instead of a boss). Sublimation redirects that same negative energy into a socially acceptable or even productive outlet, like exercise or art. Quick tip: displacement just moves the energy somewhere else; sublimation channels it into something constructive.

All three are parts of Freud's model of personality, so which one wants, which one balances, and which one judges is the real distinction. The id is made up of basic, unconscious impulses (like sex and aggression) demanding immediate gratification. The ego is the mediator between the id's demands and reality. The superego holds our internalized morals and ideals, often pushing toward perfectionism. Quick tip: id wants it now, superego says you shouldn't, ego negotiates a realistic middle ground.

The shared name is the whole problem here — students assume one is just a "milder version" of the other, but they're structurally different disorders. OCD involves intrusive, unwanted thoughts that the person usually recognizes as irrational, paired with compulsions done to relieve anxiety. OCPD is a personality disorder built around rigid perfectionism and control, with no intrusive thoughts — the person typically doesn't see their rigidity as a problem at all. Quick tip: OCD feels distressing and unwanted to the person experiencing it; OCPD usually feels justified.

Both are ways of coping with stress, so what's actually being targeted — the emotion or the problem itself — is the key distinction. Emotion-focused coping tries to manage the emotional reaction to a stressor, sometimes by avoiding it. Problem-focused coping tries to directly change or remove the stressor itself. Quick tip: emotion-focused deals with how you feel about the problem; problem-focused deals with the problem itself.

Both are symptoms that can appear in psychotic disorders, so which sense is affected — perception or belief — is what separates them. Hallucinations are sensing things that aren't actually there (seeing, hearing, feeling something unreal). Delusions are false beliefs held despite clear evidence against them. Quick tip: hallucinations are false perceptions; delusions are false beliefs.

Both are eating disorders, so the specific behavior pattern — restriction versus a binge-purge cycle — is the key distinction. Anorexia nervosa involves severe food restriction and excessive exercise to lose weight. Bulimia nervosa involves cycles of binge eating followed by compensating behaviors like vomiting, laxative use, or excessive exercise. Quick tip: anorexia is about restricting intake; bulimia is a cycle of bingeing, then compensating.

Both are depressive disorders, so duration and severity — the actual diagnostic criteria — are what separate them. Persistent depressive disorder is a milder, chronic depressed mood lasting two years or more. Major depressive disorder involves more intense symptoms, but only needs to last two or more weeks to qualify. Quick tip: persistent depressive disorder trades severity for length; major depressive disorder trades length for severity.

Both are behavior therapies that use conditioning to change a response, so whether the goal is to reduce anxiety or eliminate a bad habit is the key distinction. Systematic desensitization pairs a feared stimulus with relaxation, gradually reducing anxiety (bad paired with good). Aversive conditioning pairs an unwanted behavior with an unpleasant stimulus, to eliminate that behavior (bad paired with bad). Quick tip: systematic desensitization pairs bad with good to calm you down; aversive conditioning pairs bad with bad to stop a behavior.