Factor structure and validity of the affect intensity measure in a Swedish sample

Despite the fact that Larsen’s [Larsen, R.J. (1984). Theory and measurement of affect intensity as an individual difference characteristic. Dissertation Abstracts International. 85, 2297B (University Microfilms No. 84-22112.)] Affect Intensity Measure (AIM) is a widely used measure of affect intensity, there is an ongoing debate concerning certain of its presumed theoretical and statistical qualities and its basic, underlying assumptions. The debate has most often centered around the inventory’s dimensionality; i.e., is the AIM tapping one or more dimensions of intensity? The purpose of the present study was to investigate the dimensional structure of the Swedish translation of the AIM, to find the best structural model for the Swedish AIM data, and to study its validity. Data from 409 subjects (153 males, 256 females) were subjected to maximum-likelihood confirmatory factor analysis to assess how well different structural models fit the AIM data. The results showed that all of the multidimensional AIM models were superior to Larsen’s original 40-item uni-dimensional model, on all the fit indices. The best-fitting model was a newly derived three-factor model, based on 27 items resulting in the factors Positive Affectivity, Negative Intensity, and Negative reactivity. Validation of this model in a community sample of 208 adults clearly showed different correlational patterns between negative intensity and negative reactivity, on the one hand, and positive affectivity, on the other, which demonstrates the value of treating affect intensity as a multidimensional construct.