---
title: "Temperament — AP Psychology Definition & Exam Guide"
description: "Temperament is the inborn, biologically based pattern of emotional reactivity and self-regulation seen in infancy. It links heredity (2.1) to social development (6.2)."
canonical: "https://fiveable.me/ap-psych-revised/key-terms/temperament"
type: "key-term"
subject: "AP Psychology"
unit: "Unit 6"
---

# Temperament — AP Psychology Definition & Exam Guide

## Definition

In AP Psychology, temperament is the innate, biologically based set of individual differences in emotional, physical, and attentional reactivity and self-regulation. It shows up in infancy before much learning has happened, making it core evidence for the heredity side of nature vs. nurture.

## What It Is

Temperament is your built-in emotional thermostat. It describes how reactive a person is (how intensely they respond to new people, noise, frustration) and how well they self-regulate (calm down, shift [attention](/ap-psych-revised/key-terms/attention "fv-autolink"), control impulses). Because these differences appear in babies just weeks old, before parenting or culture has had time to shape them, psychologists treat temperament as biologically based, the raw material you're born with.

Researchers classically sort infant temperament into three patterns. **Easy** babies are cheerful, adaptable, and predictable. **Difficult** babies are intense, irritable, and react badly to change. **Slow-to-warm-up** babies are cautious and need time before engaging with anything new. Temperament isn't destiny, though. It interacts with the [environment](/ap-psych-revised/unit-1/1-interaction-of-heredity-and-environment/study-guide/K7DZeZixZvfWKSxV "fv-autolink"), especially caregiving. A difficult infant with patient, responsive parents develops differently than the same infant with harsh ones. That interaction is exactly what [Topic 2.1](/ap-psych-revised/unit-2/1-perception/study-guide/jiVFqhUY6PUoxGuf "fv-autolink") (heredity and environment) and Topic 6.2 (social development in childhood) want you to be able to explain.

## Why It Matters

Temperament sits at the intersection of two CED topics. In Topic 2.1 (Interaction of Heredity and Environment), it's a go-to example of a heritable trait, which is why [twin studies](/ap-psych-revised/key-terms/twin-studies "fv-autolink") keep showing up in questions about it. Identical twins raised apart still show similar emotional reactivity, which is strong evidence for genetic influence. In Topic 6.2 (Social Development in Childhood), temperament explains why the same [parenting style](/ap-psych-revised/key-terms/parenting-style "fv-autolink") produces different outcomes in different kids, and it feeds into attachment research, since an infant's temperament partly shapes how secure attachment looks. If an exam question asks you to explain how nature and nurture *interact* rather than compete, temperament is one of your best examples to reach for.

## Connections

### Personality (Unit 4)

Temperament is the seed; personality is the plant. Your inborn reactivity gets shaped by experience, culture, and learning into adult personality traits. Twin studies of personality lean on temperament as the heritable starting point.

### Nature vs Nurture Debate (Topic 2.1)

Temperament is the classic 'nature' exhibit. It appears in newborns and stays fairly stable, but how it gets expressed depends on environment. That makes it the perfect example of gene-environment interaction rather than nature winning outright.

### Easy/Difficult/Slow-to-Warm-Up Temperaments (Topic 6.2)

These are the three named categories the exam expects you to recognize. Know one identifying behavior for each, like a slow-to-warm-up toddler who clings at a birthday party for twenty minutes and then joins in.

### Authoritative Parenting Style (Topic 6.2)

Developmental outcomes come from the 'goodness of fit' between a child's temperament and the caregiving they receive. A difficult temperament plus warm, structured (authoritative) parenting predicts better outcomes than the same temperament plus harsh or permissive parenting.

### [Diathesis-stress model (Unit 5)](/ap-psych-revised/key-terms/diathesis-stress-model)

A reactive, anxious temperament can act as a diathesis, an inborn vulnerability. Whether it develops into a disorder like [anxiety](/ap-psych-revised/key-terms/anxiety "fv-autolink") or depression depends on environmental stress. Same heredity-environment logic, applied to psychological disorders.

## On the AP Exam

Temperament shows up most often in multiple-choice questions, usually in two flavors. The first is identification, where a scenario describes an infant's emotional excitability or fussiness and asks what it illustrates (answer: temperament, not learned personality). The second is the heredity angle, asking about the role of genes in temperament, what identical-twin studies (reared together vs. apart) tell us about inherited traits, or how gene-environment correlation works, like a temperamentally aggressive teen seeking out aggressive peers. No released FRQ has required the term verbatim, but temperament works as evidence in any AAQ or EBQ touching nature-nurture, twin research, or child development. Your job is to do two things with it: define it as innate and biologically based, and explain how it *interacts* with environment rather than acting alone.

## Temperament vs Personality

Temperament is the inborn, biologically based foundation, visible in infancy as reactivity and self-regulation. Personality is the broader, more stable pattern of thoughts, feelings, and behaviors that develops over time as temperament interacts with experience, culture, and learning. Quick test: if the question describes a baby, it's temperament. If it describes an adult's enduring traits shaped by life experience, it's personality.

## Key Takeaways

- Temperament is the innate, biologically based pattern of emotional, physical, and attentional reactivity and self-regulation, observable in infancy.
- The three classic temperament types are easy, difficult, and slow-to-warm-up.
- Twin studies support a strong genetic influence on temperament, since identical twins show similar reactivity even when raised apart.
- Temperament is the starting point for personality, but it is not destiny; outcomes depend on the goodness of fit between a child's temperament and their environment.
- On the exam, an infant's emotional excitability in a scenario question signals temperament, not learned personality.
- Temperament is one of the cleanest examples of heredity-environment interaction, linking Topic 2.1 to social development in Topic 6.2.

## FAQs

### What is temperament in AP Psychology?

Temperament is the innate, biologically based set of individual differences in emotional, physical, and attentional reactivity and self-regulation. It appears in infancy, which is why psychologists treat it as inherited rather than learned.

### Is temperament the same as personality?

No. Temperament is the inborn foundation visible in babies, while personality is the broader pattern of traits that develops as temperament interacts with environment and experience over time. Think of temperament as the raw material and personality as the finished product.

### Is your temperament fixed for life?

Mostly stable, but not locked in. The core reactivity tends to persist (a highly reactive infant often becomes a cautious adult), yet environment, especially parenting fit, shapes how that temperament gets expressed.

### What are the three types of temperament?

Easy (cheerful, adaptable, predictable), difficult (intense, irritable, resistant to change), and slow-to-warm-up (cautious at first, engages after repeated exposure). Be able to match a behavioral scenario to each type.

### Is temperament genetic?

Largely, yes. Studies comparing identical twins reared together versus apart show similar emotional reactivity across environments, pointing to heredity. But temperament also interacts with environment through gene-environment correlation, like a reactive child evoking different parenting responses.

## Related Study Guides

- [6.2 Social Development in Childhood](/ap-psych-revised/unit-6/social-development-childhood/study-guide/ahgQOpxPbSF2iDsgczgK)

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