Object permanence: an understanding that objects that continue to exist, despite being hidden from sight or awareness. An important cognitive concept that, according to Piaget, does not develop until infants are eight months old or more.
Objectivity: conducting an investigation and collecting data without the process being influenced by personal interpretation or bias.
Observation: used to describe a situation where an observer records behaviour demonstrated by a participant. An observation does not involve manipulation of an independent variable, but simply allows the observation of relationships between variables as they occur. Observation includes a variety of differing types of observation including naturalistic observation, participant and non-participant observation.
Observational learning: a process of socialisation that takes place as a result of an individual observing and imitating the behaviour of another person who serves as a model, as opposed to through direct experience. See modelling.
Observational learning: a process of socialisation that takes place as a result of an individual observing and imitating the behaviour of another person who serves as a model, as opposed to through direct experience. See modelling.
Observer bias: the tendency for observers to record data that may be biased as a result of personal expectations (e.g. awareness of the hypothesis) or motives, rather than recording what actually happens.
Obsessions: irrational thoughts and images that are normally unfounded, but over which a person may appear to have little control over, and which may ultimately affect the normal functioning of a person.
Obsessive-compulsive disorder: a disorder characterised by obsessions (uncontrollable, persistent and irrational thoughts or wishes) and compulsions (repetitive ritualistic acts).
Occipital lobe: the rearmost region of the each cerebral hemisphere, located behind the parietal lobe and above the temporal lobes. Crucial for the processing of visual information.
Occupational psychology: branch of psychology that focuses on human beings in the workplace, including job satisfaction, leadership, selection and recruitment of staff and the effect of different working conditions upon performance.
Oedipal conflict: in Freud's theory of development, the major conflict associated with the phallic stage which challenges the developing ego; named after the Greek story of Oedipus, who unknowingly killed his father and married his mother.
Oedipus complex: a term devised by Freud, to describe the intense sexual love that a young boy develops toward his mother, which is followed by jealousy and rivalry with his father to seek the attention and affection of the mother. The son subsequently demonstrates castration anxiety, fearing that his father might castrate him for his incestuous feelings towards his mother, and so represses his feelings and identifies with his father.
Offender profiling: a technique used based on an examination of the crime scene, including how the crime was committed, and a consideration of previous offender profiles, to build and predict a detailed description (including socio-demographic characteristics) of a criminal offender.
One-tailed hypothesis: see directional hypothesis.
Ontogeny: the evolution (i.e. the origin and development) of an individual organism, from conception to death.
Open-ended questions: questions that do not contain fixed, pre-determined responses that allow a respondent to answer relatively freely.
Operant conditioning: a form of learning that is determined by consequences that either reinforce or punish particular behaviours that can increase or decrease the probability of the behaviour.
Operation: the act of something being carried out.
Operation headstart: an enrichment intervention programme used in the USA in the 1960s for preschool children, aimed at changing the effects of social disadvantage.
Operational definition: a definition of a variable or condition on the basis of the exact operation or procedure that determines its existence and makes it usable. Variables can be identified by factors that are manipulated or measured.
Opportunity sample: sampling technique not based on random selection or probability; the researcher selects those who are convenient to him or her as respondents.
Oppositional defiant disorder: a disruptive pattern of behaviour of children and adolescents that is characterised by defiant, disobedient, and hostile behaviours directed toward adults in positions of authority.
Optic nerve: a group of fibres comprised of the axons of ganglion cells, that leave the eyeball, carrying information from the eye towards the brain.
Optimal mismatch theory: based on Piaget’s theory of intellectual development, aims to accelerate learning by 'mismatching' a child's current level of competence with a set of problems slightly more complex than this level. If there is a correct, optimal difference between what they can do, and what is being asked of them, children then experience a cognitive conflict and seek to find solutions through their own actions.
Oral stage: the first stage in Freud's theory of development, from birth to about 15 months, when the primary source of gratification is stimulation of the mouth and lips.
Order effects: differences in participants’ performances that occurs as a result of participants experiencing different conditions in a specific order. Subsequently, learning and practice effects can arise (whereby participants adapt and improve on later measurements) or fatigue effects (resulting in a decline in performance on later measures).
Ordinal data: data that can be rank-ordered, but intervals between ranks are not necessarily equal.
Ordinate: when plotting data on a graph, the ordinate refers to information on the vertical or y axis of the graph. The dependent variable is plotted on this axis.
Organ of corti: a receptive organ in the inner ear, whereby sound waves are changed into nerve impulses.
Organic disorder: a disorder with a known physiological cause. For instance, schizophrenia has been linked to enlarged brain ventricles and excessive dopamine.
Origin of species: the book in which Darwin proposed his theory of evolution in 1859.
Outcome study: a technique for exploring how successful a therapeutic intervention has been. For instance, an experimental group who has been given a drug may be compared to a control group that received a placebo.
Out-group: individuals who are not members of, and are not accepted by the in-group.
Overcompensation: a Freudian defence mechanism, whereby an individual attempts to offset weakness in an area of their lives by focusing on another aspect of it.
Pain management: the various measures and techniques employed to control and reduce pain.
Panic disorder: classified under DSM as an anxiety disorder, sufferers experience attacks that are unpredictable, and involve intense feelings of apprehension, anxiety and fear, and physiological symptoms of chest pain, dizziness and heavy breathing.
Paralinguistics: refers to how something is said rather than what is said, including pauses and tone of voice.
Parallel processing: an explanation of information processing, whereby two or more mental processes can be carried out simultaneously.
Paranoia: is a disturbed thought process characterised by excessive anxiety or fear, often to the point of irrationality and delusion.
Paranoid schizophrenia: a subcategory of schizophrenia, whereby an individual possesses an organised and systematic set of delusions or hallucinations, including that of persecution or jealousy.
Parapsychology: refers to a branch of psychology that seeks to explain the paranormal (which cannot be explained in terms of normal sensory experience)
Parasympathetic nervous system: combined with the sympathetic nervous system, comprises the autonomic nervous system of the body. The parasympathetic system is antagonistic to the sympathetic nervous system, by conserving and restoring bodily energy to restore the organism to a state of calm and relaxation.
Parietal lobe: the region of the cortex behind the frontal lobe and above the lateral fissure, containing the somatosensory cortex, important for the sense of touch.
Parkinson's disease: a degenerative neurological disorder, typified by difficulties in movement, for instance a continual rapid tremor in the limbs, a lack of sensory-motor co-ordination and a tendency to be continually tired. The condition is thought to be caused by problems in the production of the neurotransmitter dopamine.
Parsimony: in the philosophy of science, the principle that the simplest possible explanation should always be sought for any event.
Partial reinforcement: in operant conditioning, a contingency of reinforcement whereby a response is rewarded or punished only some of the time.
Participant: ‘subject’ in research, an individual who is the object of study or who participates in an experiment.
Participant observation: a research method involving direct participation of the researcher in the events being studied.
Participant variables: confounding effects that result from the characteristics of the participants that may influence the results, such as differences in age, memory, gender, state of hunger or level of arousal.
Paternal deprivation: loss of father, or growing up without a steady father figure may have deprivation effects, including a range of emotional and social disturbances depending on the nature and length of the absence.
Pathological: the quality of being diseased or dysfunctional. Sigmund Freud's psychological theories describe and diagnose the sources of pathological social behaviour in individuals.
Pattern recognition: the process by which we transform and organise the raw sensory information into a meaningful whole.
Pavlovian conditioning: see classical conditioning.
Peak experience: proposed by Maslow, a temporary, profound and intense experience of enhanced awareness, frequently accompanied by feelings of feeling fully alive.
Peer: an individual who is in some way equal to the person with whom they are being compared on a specific dimension.
Peer group: a social unit of (typically) same-age peers who share common values and standards of behaviour.
Perception: the process of selection, meaningful organisation and interpretation of information from the senses.
Perceptual constancy: the tendency for objects to provide the same perceptual experience despite changes in the retinal image, e.g. size constancy.
Perceptual defence: a phenomenon whereby words that have a high degree of emotional content or might be considered 'taboo' are perceptually recognised less easily than neutral valence words.
Perceptual development: the systematic development and maturation of perceptual abilities and processes over time.
Perceptual organisation: processes that combine incoming sensory information into a coherent, meaningful perceptual experience. For instance, the ability to perceive patterns and to judge size and distance in a three-dimensional scene.
Peripheral nervous system: nerves outside the spinal cord and brain (not part of the central nervous system).
Persecution: to be badly treated, oppressed or harassed usually because of beliefs, gender, race, religion or sexual orientation.
Personal space: the physical region around us that we deem to be our own, in order to regulate interactions with others.
Personality: a set of qualities that make a person (or thing) distinct from another.
Personality disorder: a group of disorders characterised by pathological trends in personality structure. It may show itself by lack of good judgment or poor relationships with others, accompanied by little anxiety and no personal sense of distress.
Personality inventory: a self-report questionnaire that is designed to measure personality characteristics, through questions on personal thoughts, feelings and behaviours. The Eysenck personality inventory (EPI) measures personality along the dimensions of neuroticism - stability and extroversion - introversion.
Person-centred therapy: see client-centred therapy
Persuasion: intentional efforts to alter attitudes.
Pervasive development disorder (PDD): refers to a group of five disorders characterised by delays in the development of multiple basic functions including socialisation and communication. The most commonly known PDD is autism.
PET (positron emission tomography) scans: a technique for imaging brain activity by recording the extent of metabolic activity in different regions of the brain during different cognitive or behavioural activities, through injecting a radioactive substance.
Phallic stage: the third stage of development in Freud's theory, from about 3 to 5 years of age, during which the source of gratification is focused on the genitals.
Phantom limb: a mysterious phenomenon experienced by amputees who often continue to experience sensations which seem to originate from the missing limb.
Phenomena: in the scientific sense, a phenomenon is an observable occurrence, pattern, or relationship between events.
Phenomenological: pertaining to the way things appear or are experienced; in the humanistic approach, a reference to the emphasis on an individual's perceptions and feelings as defining the meaning of their behaviour.
Phenotype: the observed characteristics of the individual, that manifest as a combination of genetic and environmental influences.
Philosophy: is the study of general and fundamental problems concerning matters such as existence, knowledge, truth, justice, beauty, validity, mind, and language.
Philosophy of mind: is the branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain.
Philosophy of perception: concerns how mental processes and symbols depend on the world internal and external to the perceiver.
Philosophy of science: is the study of assumptions, foundations, and implications of science.
Philosophical: of or pertaining to philosophy; a certain critical, creative way of thinking.
Phobic disorders (phobias): a type of anxiety disorder, of a persistent and irrational fear of an object or situation that is often unreasonable and unfounded in proportion to the threat, and which may interfere with an individuals function in daily life.
Phoneme: minimal units of speech that create differences in speech production and reception.
Phylogeny: evolution and development of a species. See ontogeny, which refers to the evolution and development of an individual organism.
Physical (physiological) dependence: a state where the body has adapted to and has become dependent on drugs, and sudden absence can result in withdrawal.
Physiological: relating to the way that living things function rather than to their shape or structure.
Physiologists: scientists who study living organisms and how their parts work.
Pituitary gland: a small gland located next to the hypothalamus, which regulates many endocrine functions, including the secretion of growth hormones, and secretes hormones that in turn trigger hormone secretions in other glands. For instance, a hormone called acth is released during stress, which in turn triggers the release of steroids from the cortex of the adrenal glands.
Placebo: a chemically inert substance administered instead of a real drug.
Placebo effect: when participants display improvements after being administered a placebo, on the belief that it has beneficial powers even though it has none.
Pleasure principle: Freud’s proposal that humans are motivated to achieve immediate and maximal pleasure, regardless of the cost.
Pons: the pons trigger dreaming and awakening from sleep.
Population: (or target population) the entire group to which the results of the study are intended to apply to and from which those individuals selected to participate in the study will be drawn.
Positive correlation: a relationship between two measured variables where as one measure increases the other measured variable increases too.
Positive regard: see unconditional positive regard.
Positive reinforcement: in operant conditioning, a process of increasing the likelihood of a response by immediately following the response with a desirable stimulus (a positive reinforcer).
Positive symptoms: behaviours related to a mental disorder, which do not occur in healthy persons; for example, hallucinations in schizophrenia.
Posthypnotic amnesia: a subject's inability to remember something that happened while they were hypnotised.
Post-traumatic stress disorder: a type of anxiety disorder that arises as a consequence of the experience of a traumatic event, such as a life-threatening event. Symptoms typically involve a persistent re-experience of the event, through hallucinations, recollections, flashbacks, increased anxiety and guilt.
Postsynaptic: in a synapse, of or pertaining to the neuron that bears receptors for neurotransmitter released into the synaptic cleft by the presynaptic neuron.
Preconscious: thoughts, experiences, and memories not in a person’s immediate attention but that can be called into awareness at any moment.
Predictive validity: an indicator of validity based on whether a test can accurately predict future performance on the measure in question.
Prejudice: a learned negative attitude, comprised of negative affective and stereotypes towards a person or group. Behavioural manifestation is labelled 'discrimination'
Presynaptic: refers to the axonal end of the neuron where the synapse may be inhibited or stimulated to release neurotransmitters.
Primacy effect: information presented first to a participant is more likely to be remembered than material subsequently presented.
Primary carer: the individual that holds primary responsibility for the care of an infant, often the biological mother.
Primary prevention: strategies that aim to prevent disease in currently healthy individuals, by focusing on the development of good health habits and discouraging poor ones.
Primary reinforcer: reinforcers based on innate biological significance, such as food or water.
Priming: a phenomenon whereby previous exposure to a word or situation, improves implicit memory and increases the activation of associated thoughts or memories.
Pro-attitudinal behaviour: a tendency for people to behave in a manner that is consistent, with existing, underlying attitudes.
Probability: a numerical measure of the chance that something will happen, expressed as a number between 1 (certainty) and 0 (impossibility). A probability of 0.05 is typically used in psychological investigations to represent the probability of an effect found occurring if the null hypothesis is true, ie. The results are purely due to chance factors.
Procedural memory: memory for how-to information, that we have no conscious access to, for instance, how to ride a bike.
Prognosis: when used in clinical psychology, refers to the expected eventual outcome of a disorder.
Projection: defence mechanisms whereby which unwanted thoughts are externalised or projected onto someone else.
Projective test: a type of personality assessment during which an individual is asked to interpret an ambiguous, abstract stimulus and an individual’s response will reveal unconscious and hidden feelings, motives and conflicts.
Pro-social behaviour: behaviour that is believed to help other individuals.
Protection of participants: an ethical requirement whereby researchers must minimise any risk or harm to participants.
Proximal cause: a factor which is a direct influence on behaviour, such as one's attitude or an aspect of the immediate situation.
Psyche: Jung’s term for the totality of each person’s psychic contents.
Psychiatrists: medical doctors who possess an M.D. degree and may prescribe medications for the treatment of psychological disorders.
Psychoanalytic theory: is a general term for approaches to psychoanalysis which attempt to provide a conceptual framework more-or-less independent of clinical practice rather than based on empirical analysis of clinical cases.
Psychoanalysis: a type of psychodynamic therapy devised by freud, in line with the assumptions of unconscious conflict and psychosexual development. Therapy aims for the patient to gain a deeper understanding of their own unconscious thoughts and feelings through free association and transference.
Psychodynamics: the branch of social psychology that deals with the processes and emotions that determine psychology and motivation.
Psychodynamic approach: a perspective that views behaviour in terms of past childhood experiences, and the influence of unconscious processes, drives and conflicts.
Psychological: relating to the way that living things function rather than to their shape or structure i.e. Mental or emotional as opposed to physical in nature.
Psychological dependence: the reliance upon and beliefs that are held when individuals become addicted to drugs.
Psychological disorder: a psychological disorder of thought or emotion; a more neutral term than mental illness.
Physiological psychology: is a subdivision of biological psychology that studies the neural mechanisms of perception and behaviour through direct manipulation of the brains of nonhuman animal subjects in controlled experiments.
Psychologist: means a person who by years of study, training and experience has achieved professional recognition and standing in the field of clinical psychology.
Psychology: the scientific study of the behaviour and mental processes.
Psychometric testing: the testing of individuals to measure competence in a specific area of functioning, e.g. Intelligence, personality.
Psychopath: see anti-social personality disorder.
Psychopharmacology: the study of the effects that drugs have on behaviour.
Psychophysics: the study of the relationship between physical stimuli and the mental events that arise as a result of these stimuli. The methods developed are fundamental to sensation and perception.
Psychophysiology: the branch of psychology that is concerned with the physiological bases of psychological processes.
Psychosis: any major mental disorder that involves loss of contact with reality. This usually includes delusions and/or hallucinations.
Psychotic: a person afflicted with psychosis.
Psychosocial: the psychological and/or social aspects of health, disease, treatment, and/or rehabilitation.
Psychosurgery: surgical procedures conducted on brain tissue to alleviate the symptoms of severe psychological disorder.
Psychotherapy: any variety of treatment for abnormal behaviour which is primarily verbal in nature, rather than based on the use of drugs.
Psychosexual development: in psychoanalytic theory, a description of how a child progresses through set stages that vary according to the focus of gratification (oral, anal, genital) and by the person towards which this feeling is directed at.
Public territory: a type of territory where there is a low amount of occupation and perception of ownership, for instance a beach.
Punishment: in operant conditioning, a process whereby a response is followed by a negative reinforcer, which results in a decrease in the probability of the response.