Satisfaction With Life Scale (SWLS)

SWLS measures overall satisfaction with a person’s life. It is a narrowly focused measurement tool designed to assess global life satisfaction. It does not attempt to measure constructs such as positive affect or loneliness which measure specific domains. Life satisfaction refers to a cognitive judgement process; it is a subjective self-assessment not an assessment made according to some externally imposed criteria by the researcher.

The scale was developed in the USA by Diener, Emmons, Larsen & Griffin (1985). An initial test phase of 48 items were tested on 176 University of Illinois students. Most of the initial items were related to life satisfaction however some related to positive and negative affect

By means of factor analysis this was reduced to 5 items. All items with loadings between 0.1 and 0.6 were removed. The only items remaining related to well-being and all items relating to affect were removed.

Diener et al’s study had 3 phases. The initial test phase of 48 items were tested on 176 University of Illinois students & then a second phase using a further 163 students was performed to test convergent validity between SWLS and other well-being measures. Diener et al (1985) tested the SWLS against nine other subjective well-being scales returning an average correlation of r=0.57 in convergent validity across the 9 scales. Using a test-retest timeframe of 2 months, validity was r=0.82. Internal validity using Cronbach’s alpha = 0.87. The third phase tested the scale on 53 elderly persons living in the local community with an average age of 75 years. This study showed that the scale had favourable psychometric properties.

Kobau et al 2010 tested the psychometric properties of 5 well-being measures including the SWLS. Convergent validity for SWLS was good with correlations as high as r=0.75. Internal validity between SWLS items was alpha = 0.89. Kobau et al reported that acceptable levels of test-retest reliability had been shown from 1-2 months up to 4 years.

The SWLS is a 5 item self-report questionnaire using a 7 point Likert Scale. The scale is suitable for adults of all ages and has been tested on adults ranging from 18 – 80. It is one of the most extensively used and validated instruments in well-being research. I believe it would have limited use in a clinical environment (psychopathology), however, for a positive psychology practice it could be a good assessment tool to use as a starting point to investigate underlying causes of life dissatisfaction. The scale has been translated in many languages has been shown to be valid across cultures. It is sensitive to life events and is often used as a criterion measure for new scales. The SWLS is freely available on the internet, e.g. authentic happiness website www.authentichappiness.org.

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