: Data are sets of numbers or pieces of information obtained during research studies. Data may be either qualitative (categorical and usually non-numerical) or quantitative (numerical) in nature, but in general, data are numerical pieces of information.
: When a study or experiment ends, researchers are required to "debrief" participants. In a "debreifing" a researcher explains the purpose of the study, explains the use of deception (if any was used), encourages the participant to ask questions about the study, and allows the researcher to address any harm to the participant that may have resulted from their participation in the study. Debreifing is important to make sure the participant does not feel harmed from the the study in any way.
: Decay is a type of forgetting that occurs when memories fade over time. This does NOT apply to Long Term Memory, but rather sensory storage and Short Term Memory. The main reason this occurs in sensory and/or short term memory is that we don't need to process and store all the information that we encounter in the world, so we simply don't attend to, recognize, or rehearse all the information, and this information just fades away not to be stored in our long term memories.
: This is simply a measure of sound intensity. When you are at the Smashing Pumpkins concert, standing next to the speakers, banging your head, the volume of the music is measured in decibels. The higher the decibels, the louder the music and the higher the decibel level, the more likely it is to cause damage to your auditory system....What did you say?
[top]Declarative Memory
: Declarative memory, also known as explicit memory, is a type of long-term memory in which we store memories of fact. In addition, declarative memory is divided further into semantic and episodic memories (please look those up for complete definitions). So, if you have memories of things such as when Columbus sailed to America or what day and time your baby brother was born, you have declarative memories.
[top]Defense Mechanism
: A defense mechanism is a way for the mind to protect us from being consciously aware of thoughts or feelings that are too difficult to tolerate. Since the thought or feeling is too difficult to tolerate the defense mechanism only allows the unconscious thought or feeling to be expressed indirectly in some type of disguised form. Doing this allows us to reduce anxiety that is caused by the unconscious thought or feeling.
The concept of the defense mechanism was popularized by Freud and the psychoanalytic perspective. There are several different types of defense mechanisms including repression, regression, denial (my personal favorite), projection, compensation, sublimation, reaction formation, rationalization, and hallucination.
[top]Deindividuation
: Have you ever been in a group and acted in a manner that was completely out of character for you? How about when you hear on the news that some group of people did something so violent or stupid that you just couldn't believe it? One reason this happens is that people in groups tend to lose some of their own self-awareness and self-restraint when in groups. They become less of an individual and more anonymous. In a sense, people will do things in groups they otherwise would not because they feel less responsible for their actions and less like an individual. This process of deindividuation can have powerful effects. For example, how can soldiers kill innocent children? They often answer this question by saying that they are not monsters, but that they were going along with the group and that they were just following orders, and that they were not the only ones doing it....all engaged in heinous acts of violence because, in part, they had become deindividuated.
: From French, literally meaning "already seen,' Déjà vu is that eerie sense of "I've experienced this before." This may occur from the current situation producing some clues that may subconsciously trigger retrieval of an earlier experience. Deja Vu is that eerie sense of "I've experienced this before." This may occur from the current situation producing some clues that may subconsciously trigger retrieval of an earlier experience. As Yogi Berra said, "It's like deja vu all over again."
: A delta wave is a type of brain wave that is large (high amplitude) and slow (low frequency), and is most often associated with slow wave sleep (stages 3 and 4; often referred to as deep sleep). Delta waves, like other brain waves, are measured using an electro-encephalogram (EEG).
: People with certain psychological disorders (or those having a psychotic episode), such as schizophrenia, may demonstrate delusions, or false beliefs, often of persecution or grandeur. For example, a schizophrenic may insist they he is a great football player who has won many awards and has been the hero of many games, even though in reality, he was never even been on a football team.
[top]Demand Characteristic
: Sometimes during an experiment, a participant might pick up on some clue or bias from the researcher, the situation, or something about the experiment that gives the participant and idea of what type of response the researcher is looking for. This doesn’t mean that the participant is right, just that something makes them act in a way they think is what the researcher wants and not necessarily in their normal manner. This is similar to oberver bias except that the bias is found in the participants and not the observers of the research.
: Dendrites are the branch-like structures of neurons that extend from the cell body (soma). The dendrites receive neural impulses (electrical and chemical signals) from the axons of other neurons. The signal always travels in the same direction - the signal comes into the neuron through the dendrites, through the cell body (soma), to the axon, and then out the terminal buttons to the dendrites of the next neuron. In this way information travels all around your body by going from neuron to neuron.
: Denial is a defense mechanism in which a person unconsciously rejects thoughts, feelins, needs, wishes, or external realities that they would not be able to deal with if they got into the conscious mind. For example, when people are told that they have a terminal illness and are going to die in a short period of time, the news can be so overwhelming that they enter into a state of denial--they refuse (on every level) to accept that they are going to die soon because it is much too painful to handle.
[top]Dependent Variable (DV)
: In an experiment there are two variables; the independent variable (IV) and the dependent variable (DV). In the most basic sense, you need two variables because as a researcher, you want to be able to examine if something (a drug, a therapy, a teaching technique, whatever) has an effect on some participant (person, people, animals, etc.). To accomplish this, you not only need something to examine (and manipulate - this is the IV), but also something to measure the effect the IV has (this is the DV). Thus, we can define the DV as the variable that is being measured. It is this variable that we, as the researchers, look at for change. IF there is a change, we may conclude that the IV affected the DV. The ultimate here is to establish that the IV caused the change in the DV (this is the magical "cause-effect" relationship).
[top]Depressants
: Depressants are drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow down body functions. Many people think that alcohol is not a depressant and actually makes them have more fun. However, what alcohol does is lower inhibitions, so you may act in ways you otherwise would not. Also, it diminishes your senses - makes you less alert, less attentive, less "sharp", essentially depressing the nervous system.
[top]Depressive Realism
: Depressive Realism is the tendency for mildly depressed people to make judgments that are typically more accurate than people who are not depressed. Those who are not depressed often make judgments and attributions that are self-serving. For example, if you did well on a psychology test you might say that you did so because you're a genius and know everything about psychology. This would be a pretty self-serving attribution, wouldn't you say? But a mildly depressed person who got an A might make a more accurate attribution such as saying it was not because she is a genius, but because she studied well or the test was particularly easy. Your way might make you feel better, but it also might be less accurate.
[top]Deprivation Study
: A deprivation study is a form of research in which an organism is prevented from having something they want or need for a designated period of time in order to examine the effect the deprivation has on the organism. For example, I used to work in a sleep lab where we often deprived people of sleep for days at a time. During the study we presented participants with all sorts of tests to see the effects sleep deprivation had on their cognitive functioning, motor skills, coordination, and many other factors.
[top]Depth Perception
: Depth perception is the ability to judge the distances of objects, which also allows us to see them in three dimensions. Obviously, images that strike the retina are two dimensional, but because our visual systems have the capacity to interpret stimuli in terms of relative depth, we see these objects not as flat, but as having some depth.
[top]Descriptive Statistics
: Descriptive statistics are used by researchers to summarize and "describe" data found during research. Typically researchers deal with lots of data and descriptive statistics provide a way for the researchers to summarize the main properties of a large group of data into just a few numbers. This lets the researcher show what the data are without tons and tons of numbers. Some examples of descriptive statistics are frequency distributions, measures of center (i.e., mean, median, mode), range, and standard deviation. (This is not a complete list of descriptive stats)
[top]Developmental Psychology
: Developmental psychology is the branch of psychology that studies physical, cognitive, and social change of humans throughout their life cycle. Some argue that developmental psychologists study changes over time which all psychologists study, not just developmentalists. However, the difference is that the topics studied by developmental psychologists revolve around the maturation and aging process; what affects it and what it affects. For example, a developmental psychologist and myself may each conduct a study addressing how children of different ages perform on a particular test. The developmental Psychologist would be concerned with the differences between the age groups, why they performed differently, what developmental issues may be the causal factors in the differences, etc., while I may explain the differences in terms of the test, not the developmental differences of the children (i.e., the test is age appropriate, can we use it on people of other ages, what does having an age difference mean on whatever the test actually measured, etc.).
[top]Difference Threshold
: The difference threshold, also known as the just noticeable difference (jnd), is the minimum difference in stimulation that a person can detect 50 percent of the time. We experience the difference threshold as a just noticeable difference. For example, let's say I asked you to put your hand out and in it I placed a pile of sand. Then, I add tiny amounts of sand to your hand and ask you to tell me when you notice any change in the overall weight. As soon as you can detect any change in the weight, that difference between the weight of the sand before I added that last bit of sand and the amount of sand after I added it, is the difference threshold.
[top]Differential Psychology
: This is the field of psychology established by Galton, that studies all the behavioral and cognitive differences between people including individual differences in personality, intellect, and physical characteristics.
[top]Differentiation
: Differentiation typically refers to a developmental process when a skill becomes more sophisticated and broken into subsets. For example, a child may first learn the skill of walking, which can later become more sophisticated and break into skipping, running, jumping, and more. The child has not reached a new level of walking (if you will), but rather differentiated one skill into multiple subsets.
[top]Discriminant Validity
: Discriminant validity is the degree to which scores on a test *do not* correlated with scores from other tests that *are not* designed to assess the same construct. For example, if discriminant validity is high, scores on a test designed to assess aggressiveness should not be positively correlated with scores from tests designed to assess intelligence.
[top]Discrimination
: Discrimination is a term that is used in both classical and operant conditioning. In classical conditioning, it refers to an ability to distinguish between a conditioned stimulus (
CS) and other, similar stimuli that don't signal an unconditioned stimulus (US). For example, if Pavlov's dog had developed discrimination, it would have salivated to the tone that had been paired with the delivery of the meat powder, and not a similar tone with a slightly different pitch. In operant conditioning, the definition is essentially the same, but here the organism discriminates between a learned, voluntary response and an irrelevant, non-learned response. For example, a dog that has learned to sit when a person says "sit" in order to receive a treat, but the dog does not sit when a person says "bit".
[top]Displacement
: According to Freudian psychoanalytic theory, displacement is when a person shifts his/her impulses from an unacceptable target to a more acceptable or less threatening target. For example, if you are very angry at your teacher because you did poorly on a test and think the reason for your poor performance is because the teacher asked tricky, unfair questions, you may become angry at your teacher. But, you obviously can't yell at your teacher (really, you can't!), hit your teacher, or express your angry in any other hostile way toward the teacher, so you go home and "displace" your anger by punching your little brother instead.
[top]Dissociation
: Dissociation is a split in the mind in which there can be two independent streams of consciousness occurring at the same time, allowing some thoughts and behaviors to occur simultaneously with others. According to some, dissociation is the foundation of hypnosis - the hypnotized person is able to maintain control of certain thoughts and behaviors, while others are being influenced by the hypnotist.
[top]Dissociative Disorders
: Dissociative disorders are disorders such as psychogenic fugue, multiple personality, and psychogenic amnesia in which a person's conscious awareness becomes separated (dissociated) from previous memories, thoughts, and feelings. When this happens, the person is unable to recall certain events that happened in their lives. For example, you may have heard of people committing heinous crimes and them claiming to have no recollection whatsoever of the event. This would be a case of psychogenic amnesia.
[top]Dissociative Fugue
: Dissociative Fugue (also known as just Fugue) is a really interesting type of disorder in which a person suffers a bout of amnesia and then flees their home and identity. Often the person will travel far away from their home, assume a new identity, and live as a different person until they "snap" out of their amnesic state.
The DSM criteria for Dissociative Fugue are:
1. The main disturbance is sudden, unexpected travel away from home or one's customary place of work, with inability to recall one's past.
2. Confusion about personal identity or assumption of a new identity (partial or complete).
3. The disturbance does not occur exclusively during the course of Dissociative Identity Disorder and is not due to the direct physiological effects of a substance (for example, a drug of abuse, a medication) or a general medical condition (for example, temporal lobe epilepsy).
4. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
: This term refers to the “bad” type of stress (the opposite of Eustress), and occurs when we have excessive adaptive demands placed upon us. This occurs when the demands upon us are so great that they lead to bodily and mental damage. Distress is damaging, excessive or pathogenic (disease producing) stress.
[top]Divergent Thinking
: A cognitive process (a mode of critical thinking) in which a person generates many unique, creative responses to a single question or problem. This is different from convergent thinking which attempts to find a single, correct answer to a problem.
: Your genetic makeup (who you are genetically which controls things like eye color, hair color, bone structure, organ size, etc.) is controlled by the paring of the chromosomes contained from the female's egg (23 chromosomes from her) and the chromosomes from the male's sperm (23 from him too) (you know how those chromosomes come together, right??). Each of the 46 total chromosomes is made up of long threads of a very specific type of molecule called DNA, or deoxyrivonucleic acid. It goes one step further - each molecule of DNA is made up of thousands of genes, which determine your "genetic makeup". So you see, DNA is really the carrier of the genetic material that determines who you are (genetically).
[top]Door-in-the-Face Technique
: This is a technique used to get compliance from others (to get them to behave in a way you want) in which a large request is made knowing it will probably be refused so that the person will agree to a much smaller request. The real objective is to get the person to agree to the small request, which is made to seem very reasonable because it is compared to such a large, seemingly unreasonable request. In essence, the large request gets you the "door in the face" when you ask it. For example, someone might ask you to give to give 5 hours of your time a week for the next year as a volunteer to a charity. After hearing this offer you may think it is a huge request, after which you may be asked to, instead of committing to all this volunteering time, to just donate a small amount of money. Compared to the time commitment, this request seems much more acceptable.
[top]Double-Blind Procedure
: This is one type of experimental procedure in which both the patient and the staff are ignorant (blind) as to the condition (or group) that the participant is in. This would make it impossible for the participant or researcher to know if the participant is receiving the treatment (for example a drug) or a placebo. This type of design is commonly used in drug evaluation studies, and is used to prevent the researchers from acting differently to people in one group, or from giving the participant any information that could make them act and/or behave unnaturally.
[top]Down Syndrome
: Down syndrome is a condition of mental retardation and associated physical disorders caused by an extra
Chromosome. Each person has 23 pairs of chromosomes, one pair from each parent. A person with down syndrome has a 3rd chromosome on the 21st pair. The results are both mental and physical, and often include small eyes, and hands, protruding tongues, short necks and fingers. There are all different levels of the disorder, and the probability of a child being born with it increases as the mother's age increases; this is especially true as the mother becomes middle aged.
: An aroused state of psychological tension that typically arises from a need. A drive, such as hunger or thirst, motivates the organism to act in ways that will reduce the tension. So, for example, when you become hungry (tension caused by need for food) you are motivated to eat (method of reducing the tension).
[top]Drive Reduction Theory
: How do you know when it is time to get a glass of water? You know because you get this feeling of being thirsty which motivates you to reduce the thirst by drinking water. This is what happens according to drive reduction theory. According to this theory, some physiological need (need for water) occurs that creates a state of tension (you feel thirsty) which in turn motivates you to reduce the tension or satisfy the need (drink water).
: The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders is a system used for classifying psychological disorders. This is the most widely accepted set of guidelines and definitions for mental disorders, and is often referred to as, "the clinician's bible". There are approximately 230 disorders listed in the DSM-IV-R which are organized into 17 categories.
: DSM-IV stands for the title of the book, Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition). This book is published by the American Psychological Association and is the primary book used in diagnosing psychological problems. You can think of this book as the "guide" for diagnosing psychological disorders used by clinical psychologists, counselors, and therapists. The DSM-IV has all the definitions of disorders, criteria for diagnosis, etc.
: Dualism is the presumption proposed by Descartes that the human mind and body are two distinct entities that interact with each other to make a person. Descartes reasoned that the mind and the body communicate with each other through a small structure at the base of the brain called the pineal gland.
: The presence of two entities. For example, two people, two animals, etc. Some have argued that a dyad can be considered a "group", so a dyad could be considered a group consisting of two organisms. The key is that there are 2.
: Dysphoria is a psychological state that causes someone to experience feelings of anxiety, restlessness, and depression. This is not necessarily a diagnosible disorder like schizophrenia or something else that would be identified in the DSM-IV, but it is more of a state of being.
: Dysthymia is a chronic type of depression that occurs on most days and lasts for a period of 2 or more years. In children and adolescents, mood can be irritable and duration must be at least 1 year. Also, the person has to display at least two of the following symptoms during the 2 year period: poor appetite or overeating, insomnia or hypersomnia, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, or feelings of hopelessness.
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