Glossary page 5

Question 1

phase advance

Answer 1

going to bed earlier than usual and getting up earlier than usual
– that is, the shift of sleep to an earlier time in the 24-hour cycle

Question 2

phase delay

Answer 2

going to bed later than usual and getting up later than usual – that
is, the shift of sleep to a later time in the 24-hour cycle

Question 3

pheromones

Answer 3

chemicals secreted by an animal that influence the behaviour or
development of other animals of the same species

Question 4

piloting

Answer 4

running a small-scale trial of a research study – before the full study is
conducted – to check that the procedure works and for any problems in the
design

Question 5

pineal gland

Answer 5

a part of the brain that secretes melatonin

Question 6

placebo effect

Answer 6

an improvement (usually in health) that is measurable or felt,
that is not attributable to a treatment

Question 7

plagiarism

Answer 7

presenting someone else’s work as your own – a serious academic
offence

Question 8

population validity

Answer 8

a study has population validity if the results can be extended
beyond the sample to a wider group

Question 9

predictive validity

Answer 9

the ability of a test or measure to predict something that,

theoretically, it should be able to predict

Question 10

primary insomnia

Answer 10

where there is no obvious medical or psychological reason for
the failure to sleep, early waking or the failure to get to sleep

Question 11

probability

Answer 11

how likely it is that something will happen; usually expressed as a
number between 0 and 1

Question 12

pseudohermaphrodite

Answer 12

someone with typical internal organs but atypical or

ambiguous external genitalia

Question 13

psychological androgyny

Answer 13

where people are both highly masculine and highly

feminine. It is a psychologically healthy state

Question 14

psychopathology

Answer 14

branch of psychology concerned with abnormal behaviour

Question 15

psychotic

Answer 15

relating to psychosis (plural = psychoses), a serious mental disorder

Question 16

psychosocial factors

Answer 16

factors in the social environment that have an effect on

the individual

Question 17

psychosurgery

Answer 17

brain surgery where brain tissue is cut or removed in an attempt
to relieve the symptoms of psychiatric illness

Question 18

purposive sampling

Answer 18

a sampling technique that involves selecting participants
deliberately, to enable a topic of interest to be studied or because they have
some interesting feature

Question 19

random sample

Answer 19

a sample where every member of the target population has an

equal chance of being chosen to be included in the sample

Question 20

reductionist

Answer 20

breaking down complex phenomena into more simple components

Question 21

relapse

Answer 21

a return to addictive behaviours by an individual after a period when
they had given up their addictive behaviours