IB Psychology HLTopic 3 — Group BehaviourPaper 1 & 2Sociocultural approach~9 min read
Commitment as a Compliance Technique
You agreed to look after your niece for an afternoon. Somehow you are now looking after your niece and your nephew for eight hours. Nobody forced you and nobody tricked you. You were simply asked in the right order. That is prior commitment, and once you can see it you will notice it everywhere.
📘 What you need to know
Compliance is responding positively to a request or an offer. Requests can be explicit (a charity asking for a donation) or implicit (an advert for a phone deal).
People are usually aware they are being targeted. Compliance techniques are not subliminal, but they can be subtle and sophisticated.
Commitment is one such technique. Prior commitment means people are more likely to behave a certain way if they have already been encouraged to behave that way.
It works by securing active and willing participation — an agreement or intention — from someone who had no such plan.
Prosocial behaviour is any behaviour that benefits another person or society as a whole.
Governments, schools and global corporations all use commitment to promote prosocial behaviour and their own core values.
Dickerson et al. (1992) showed that students who both signed a poster and answered a questionnaire took the shortest showers.
Why commitment works
Once you have publicly agreed with something, doing the opposite makes you inconsistent with yourself. Most people find that uncomfortable, so the cheapest way out is to act in line with what you said. The technique never argues with you; it just gets you to state a position first.
The move in one line
get a small, willing agreement first → the matching behaviour becomes much more likely
The word willing is doing real work. A commitment extracted by force does not produce the effect, because the person can tell themselves they had no choice. It has to feel like their own decision.
Research support: Dickerson et al. (1992)
Aim: to investigate the extent to which prior commitment is linked to prosocial behaviour.
Participants: 80 female students from a college in Santa Cruz, California, all competitive swimmers, obtained through opportunity sampling.
Procedure: a field experiment with four conditions. In condition 1 a female confederate stopped each swimmer on her way to the showers and gave her a questionnaire about her own water use. In condition 2 the swimmer was asked to sign a poster reading “please conserve water, take shorter showers”, and had her attention drawn to water-conservation posters around campus. In condition 3 she did both. Condition 4 was the control, with no approach at all. A second confederate, already in one of the shower cubicles, timed each shower.
Results: see the chart below. The condition-3 participants, who had made the fullest prior commitment, showered for the shortest time.
Conclusion: making a prior commitment to use less water influences the later prosocial behaviour of actually using less water.
The dose-response pattern is what makes this convincing. More commitment produced more behaviour change, in the order the theory predicts.
Why the questionnaire counts as a commitment. It looks like data collection, but answering questions about your own water use forces you to think about your behaviour and state a position on it. That is a private commitment. Signing the poster is a public one. Condition 3 stacked both, which is why it produced the biggest change.
Prosocial behaviour and who promotes it
Governments — recycling adverts, energy-saving campaigns, public health messaging.
Schools — building prosocial habits in children before those habits have to compete with anything else.
Global corporations — campaigns that promote sharing, kindness and positive feeling rather than the product directly.
The aim in every case is to communicate core values: care and kindness towards others, being a responsible citizen and custodian of the planet, and upholding legal, moral and ethical standards. Getting a prior commitment is a practical step towards producing the behaviour, because it fosters a sense of shared responsibility and a duty of care.
Evaluation
Strengths
Highly applicable. Understanding commitment helps in a wide range of prosocial contexts — recycling, healthy eating, anti-bullying campaigns.
Naive participants and high ecological validity. The swimmers had no idea they were in a study, so they could not produce demand characteristics. As far as they knew they were doing what they always did after training, so the behaviour was natural and unforced.
A real behavioural measure. The dependent variable was seconds in a shower, not a self-reported intention. That is much stronger evidence than asking people what they would do.
Limitations
Intentions rarely become actions. People say they will use fewer plastics; whether they do is something researchers may never find out. This study is unusual precisely because it measured the behaviour.
Only one confederate did the timing. She may have missed the start or end of a shower. A second timer would have allowed a reliability check.
Narrow sample. 80 female competitive swimmers at one Californian college, obtained by opportunity sampling.
Short-term effect only. We know what happened in that one shower. Nobody followed the swimmers for a month.
EXAM QUESTION
Explain the use of one compliance technique. [9]
Step 1: define compliance, then commitmentResponding positively to a request; prior commitment as active, willing agreement.Step 2: explain the psychology, do not just describe itActing against your own stated position feels inconsistent, so the easier route is to follow through.Step 3: use Dickerson with the actual numbersFour conditions, 301.8 down to 220.5 seconds, dose-response pattern.Step 4: one strength, one limitationNaive participants and real behaviour measured, against a single timer and a narrow sample. For a 9-mark answer, that is enough.Keep an explain answer tight — do not write a 22-mark essay
Link to concepts
Causality
This study takes place in the field but is designed like a lab experiment as far as that is possible outdoors. Operationalising an independent variable is often impossible in field research, which makes this design unusual. Four manipulated conditions and a standardised procedure give it reliability and make it replicable — though never perfectly, because the human variables of approaching swimmers and timing showers can never be repeated exactly.
Responsibility
There are genuine ethical problems here. The students did not know their showering was being timed (deception), their privacy was breached given the intimate setting in which the data was collected, and they could give neither informed consent nor exercise a right to withdraw. The very features that give the study its ecological validity are the ones that make it ethically difficult, and a good answer says so directly.
💡 Exam tip
Quote the control figure alongside the others. Without 301.8 the other numbers mean nothing.
Explain why naive participants raise ecological validity: no demand characteristics.
Point out the ethics-versus-validity trade-off explicitly. It is the sharpest thing you can say about this study.
Use “prosocial behaviour” as a defined term, not as a synonym for “being nice”.
The dose-response pattern (one commitment beats none, two beat one) is a strong evidential argument.
Say the design is a field experiment and name the IV and DV.
⚠ Common mix-up
Confusing compliance with obedience. Compliance follows a request; obedience follows an order from authority.
Thinking compliance techniques are subliminal. People are usually aware they are being asked.
Forgetting condition 4. The control is what turns four numbers into a finding.
Saying the study was unethical and stopping there. Name the specific breaches: deception, privacy, consent, withdrawal.
Treating the questionnaire as a neutral measurement. In this design it is part of the manipulation.
Generalising to men, other ages or other behaviours. The sample was 80 female swimmers.
Up next: Why People Conform to a Group — commitment changes what one person does. Conformity is what happens when everyone else in the room disagrees with your own eyes.
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