# Peer influence

> IB Psychology · IB Psychology 2027 First Assessment
> Source: https://www.owlsprep.com/study/ib-psychology-hd-peer-influence/

The role of peer influence in the development of self.

## Learning objectives

- The role of peer influence in the development of self.

## How often is this tested?

Based on OwlsPrep's analysis of official CIE IB_PSYCH P2 past papers (2019–2025): **Peer influence** appears **4 times** in the last 7 years — **1.4%** of all P2 questions (4 of 288).

Most-tested forms: Essay: Discuss (22 marks) (4).

*Small sample — indicative only.*

## Core concept

Peer influence is the way friends and age-mates shape a young person's attitudes and behaviour, especially in adolescence when peers' approval matters most. It can push behaviour in either direction — encouraging risk-taking, or supporting achievement — often by changing what the person believes is normal or high-status among peers. Peers thus become a major force in the development of self, alongside family and culture.

## Key studies

IB Psychology answers must be supported by named studies. Learn these to cite as evidence:

**Cohen and Prinstein (2006)** — In a manipulated online chatroom, adolescents shifted their attitudes and willingness to behave aggressively/riskily toward the responses of peers they believed were high-status. — *An experimental demonstration — manipulating perceived peer norms changed behaviour, evidence for genuine influence rather than mere similarity.*

**Giletta et al. (2021)** — A meta-analysis of longitudinal studies found a small but robust and statistically significant effect of peer influence on adolescents' behaviour across countries and ages. — *Shows the effect is real and general, while quantifying that it is modest.*

## Evaluation (AO3)

**Strength — experimental and meta-analytic support** — Cohen & Prinstein establish causal direction under control, and Giletta's meta-analysis shows the effect replicates broadly — a rare pairing of internal and external validity.

**Limitation — the effect is modest and hard to separate from selection** — The averaged effect is small, and outside experiments young people choose similar friends (selection), so correlational peer 'influence' is easily overstated.

## Scope

> **note**
>
> Peer influence on the developing self is the focus. The general group-pressure process is conformity (SOC_3); norm transmission is HD_6.

## Common pitfalls

- **Wrong:** If teenagers and their friends behave alike, the friends must have caused it (peer pressure).
  - Why it fails: A frequently penalised misconception in IB Psychology exams.
  - Correct: Similarity can come from SELECTION (similar teens befriend each other) as much as from influence. Showing peers change behaviour needs experimental or longitudinal evidence (Cohen & Prinstein; Giletta), not just a correlation.

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