27 of the Psychology glossary’s terms, each with the part of the syllabus where you first meet it.
A change in behaviour in response to a direct order from a person who is seen as having legitimate authority.
An excess of body fat that presents a risk to health; in adults it is usually operationalised as a body mass index of 30 kg/m² or more.
The sum of the surroundings, opportunities and conditions of life, such as food supply, marketing, transport and urban design, that promote weight gain in a population.
The understanding that objects continue to exist even when they cannot be seen, heard or touched; in Piaget’s theory it develops in the sensorimotor stage.
The aim of collecting and interpreting evidence in a way that does not depend on the researcher’s personal views or expectations, so that another researcher following the same procedure would reach the same result.
A research method in which the researcher watches and records behaviour as it happens, either in a natural setting or in a controlled one, without manipulating an independent variable.
A data collection tool for observations that lists operationalised behavioural categories and sets out how and when each occurrence is recorded, usually as tallies.
Learning that takes place by watching the behaviour of others and its consequences, without the learner having to perform the behaviour or be reinforced directly.
A distortion in observational data caused by the observer’s expectations, beliefs or interpretations affecting what they notice and how they record it.
A mental health disorder involving unwanted, intrusive thoughts (obsessions) and repetitive behaviours or mental acts (compulsions) performed to reduce the anxiety they cause.
The lobe at the back of each cerebral hemisphere, which contains the visual cortex and processes information from the eyes.
A significance test used with a directional hypothesis, which places the whole significance level in one tail so only an effect in the predicted direction can be significant; a two-tailed test splits it between both tails.
A question that allows participants to answer freely in their own words, which produces qualitative data.
A form of learning in which the likelihood of a voluntary behaviour changes as a result of its consequences: reinforced behaviour becomes more likely and punished behaviour less likely.
The process of stating exactly how a variable will be manipulated or measured in observable terms, so that a construct becomes measurable and the procedure can be repeated by others.
A sampling technique in which the researcher uses whoever is available and willing at the time, such as students in a class; also called convenience sampling.
The tendency to believe that one is more likely than other people to experience good events and less likely to experience bad ones.
Changes in performance caused by the order in which conditions are completed rather than by the independent variable, such as improvement through practice or decline through fatigue or boredom.
Data that can be put in order or ranked (such as ratings on a 1–5 scale), where the gaps between the values are not known to be equal.
A social group to which a person feels they do not belong and against which their own group is compared.
A score that is far higher or lower than most of the other scores in a data set; one common rule treats any score more than 1.5 interquartile ranges beyond a quartile as an outlier.
The tendency for people’s confidence in their judgements, knowledge or abilities to be greater than the accuracy of those judgements justifies.
The tendency of human children to copy all of an adult’s demonstrated actions, including steps that are clearly unnecessary for reaching the goal.
The decrease in intrinsic motivation for an enjoyable activity that can follow an expected external reward for doing it, as the activity comes to be seen as done for the reward.
Siegler’s continuous model in which children use several strategies at the same time and gradually shift towards more efficient ones, so each strategy’s frequency rises and falls like a wave.
An observation in which the participants know that they are being observed and usually why.
A hormone and brain chemical messenger, released by the pituitary gland and by neurons in the brain, involved in childbirth, breastfeeding and social behaviours such as bonding and trust.