The negative and positive affect scale (NAPAS)

Abstract

The Negative and Positive Affect Scale (NAPAS) is a concise self-report instrument designed to measure the two primary dimensions of subjective experience: positive affect and negative affect. Developed originally by Mroczek and Kolarz (1998), the scale assesses the frequency and intensity of these emotional states experienced over a specified period, typically the past 30 days. The NAPAS is known for its strong psychometric properties, including acceptable reliability and validity across its original 12-item version and a later refined 10-item version developed by Joshanloo (2017), making it a valuable tool in developmental and personality psychology research.

Keywords

Affect, Positive Affect, Negative Affect, NAPAS, Subjective Well-being, Emotional States, Psychometrics, Mroczek and Kolarz, Joshanloo.

Authors

Mroczek, D. K., Kolarz, C. M., Joshanloo, M.

Purpose

The primary purpose of the NAPAS is to provide a brief, reliable, and valid assessment of an individual’s dispositional or recent experience of positive and negative emotionality. This tool is crucial for research requiring the differentiation between these two independent dimensions of affect, as conceptualized within dominant models of happiness and subjective well-being.

The scale serves to quantify the extent to which a person experiences feelings ranging from sadness and hopelessness (the negative cluster) to cheerfulness and satisfaction (the positive cluster) within a defined temporal window, usually 30 days. This measurement allows researchers to study emotional stability, developmental trends in emotion, and links between affect and various health outcomes.

Construct

The NAPAS measures the psychological construct of Affect, specifically focusing on the widely accepted two-factor model which posits that positive and negative affect are distinct, orthogonal dimensions rather than opposite ends of a single continuum. Positive Affect reflects engagement, enthusiasm, and energy, while Negative Affect reflects general distress, unpleasant engagement, and subjective unhappiness, including states like sadness, nervousness, and restlessness.

The scale aligns with theories linking affective experience to overall subjective well-being (SWB), where high positive affect and low negative affect contribute significantly to life satisfaction and happiness. The instrument’s structure ensures that these constructs are measured independently, supporting its use in studies focused on personality, aging, and mental health outcomes.

Validity

The NAPAS demonstrates strong evidence of validity across both its 12-item and 10-item versions. Initial validation by Mroczek and Kolarz (1998) established its ability to accurately measure the intended constructs.

Subsequent research by Joshanloo (2017) focused specifically on the scale’s criterion validity and factorial structure, confirming that both versions are highly correlated with established measures of subjective well-being and personality traits. Furthermore, studies have supported the scale’s utility in cross-cultural contexts and its measurement invariance across gender and different cultural groups (e.g., Iran and the USA), demonstrating robust generalizability.

Reliability

The internal consistency and stability of the NAPAS have been reported as acceptable to very good across various samples. The initial psychometric assessment indicated that the scale has demonstrated acceptable reliability, supported by the key references provided by the original authors and subsequent refinement studies.

High internal consistency (typically measured by Cronbach’s alpha) ensures that the items within the Positive Affect subscale consistently measure positive feelings, and similarly, items within the Negative Affect subscale consistently measure negative feelings. The strong psychometric foundation of both the original 12-item scale and the streamlined 10-item version ensures confidence in measurement precision for research applications.

Factor Analysis

Factorial structure investigations have consistently supported the hypothesized two-factor model underlying the NAPAS. This structure cleanly separates the items into two distinct, yet potentially correlated, dimensions: a factor representing Positive Affect and a factor representing Negative Affect.

Joshanloo’s work (2017, 2016) specifically focused on confirming the factorial structure of both the original and short versions, establishing that they maintain factorial integrity and are suitable for use in varied cultural settings. This two-factor separation is critical for accurately assessing affective states, ensuring that the scale does not conflate the presence of positive feelings with the absence of negative feelings, or vice versa.

Instrument

Test Type: Self-report psychological inventory/Affective measure

Format: Likert-type scale (5-point response options) administered via questionnaire. Two versions exist: 12-item (original) and 10-item (shortened).

Language Available: English (Original); validated versions exist in other languages, including Persian/Farsi (used in studies by Joshanloo).

Population Group: General population, utilized extensively in studies of aging, developmental psychology, and subjective well-being.

Age Group: Primarily adults and older populations (given its original application in developmental perspectives on aging).

Population Details: Used across various demographics to measure chronic or recent emotional experience.

Test Methodology: Respondents rate how much of the time they felt specific emotions or states during the past 30 days, using a 5-point frequency scale.

Keywords

Emotionality, Developmental Psychology, Measurement Invariance, Happiness, Affective States, Self-Report, Scale validation, Two-Factor Model.

Authors

Author ORCID Identifier: N/A (Information not provided in source)

Affiliation Email addresses: N/A (Information not provided in source)

Correspondence Address: N/A (Information not provided in source)

Permissions & Fee and Test Year

The scale was initially introduced in 1998 in the Journal of Personality and Social Psychology by Mroczek and Kolarz. The shortened 10-item version was validated in 2017 by Joshanloo. Information regarding specific permissions, usage fees, or commercial copyright holders for the NAPAS is not detailed in the source material. Researchers typically rely on standard academic policies for scales published in major psychological journals, but commercial or wide-scale administrative use may require contacting the corresponding authors.

Test Year (Original Publication): 1998

Reference’s

• Mroczek, D. K., & Kolarz, C. M. (1998). The effect of age on positive and negative affect: a developmental perspective on happiness. Journal of personality and social psychology, 75(5), 1333-1349.
• Joshanloo, M. (2017). Factor structure and criterion validity of original and short versions of the Negative and Positive Affect Scale (NAPAS). Personality and Individual Differences, 105, 233-237.
• Joshanloo, M. (2016). Factor structure of subjective well-being in Iran. Journal of Personality Assessment, 98(4), 435-443.
• Joshanloo, M., & Bakhshi, A. (in press). The factor structure and measurement invariance of positive and negative affect across gender and cultural groups: a study in Iran and the USA. European Journal of Psychological Assessment.

Items of the The negative and positive affect scale (NAPAS)

The following items constitute the original 12-item and subsequent 10-item versions of the Negative and Positive Affect Scale (NAPAS). Response options use a 5-point frequency scale.

Original 12-Item Version

The NAPAS is a short measure of affect. It was developed and introduced in Mroczek and Kolarz (1998). Its factorial and criterion validity has been investigated in Joshanloo’s recent studies. The scale shows very good psychometric qualities.

During the past 30 days, how much of the time did you feel …

Scoring key: Negative affect 1-6; Positive affect 7-12.

10-Item Version

Joshanloo (2017) developed a 10-item version of the NAPAS. The long and short versions have similar psychometric properties.

During the past 30 days, how much of the time did you feel …

Scoring key: Negative affect 1-5; Positive affect 6-10.

Response Formats

Two response formats can be used with the NAPAS, both utilizing a 5-point scale: