A South African adaptation of the international affective picture system: The influence of socioeconomic status and education level on picture ratings

The International Affective Picture System (IAPS) is used globally in emotion research. However, normative studies in diverse contexts do not consider the influence of education and socioeconomic status (SES) on picture ratings. We created the South African Affective Picture System (SA-APS) for use in low- and middle-income countries (LMICs) by replacing some original IAPS images with pictures featuring more diverse groups of people and culturally appropriate stimuli. Healthy South African adults from higher and lower education/SES backgrounds (n = 80; n = 70 respectively) provided valence and arousal ratings for 340 images from the original IAPS and 340 images from the new SA-APS. Overall, their ratings of SA-APS images were better aligned with the US normative standards than their ratings of IAPS images, particularly with regard to valence. Those with higher SES/education rated IAPS images differently from those with lower SES/education (e.g., valence ratings of the latter were similar to US normative standards, whereas those of the former were more negative). Regression modelling indicated that sex and SES significantly predicted the current sample's IAPS and SA-APS ratings (e.g., women and higher-SES participants rated high-arousal images as being significantly more arousing than men and lower-SES participants); hence, we created regression-based norms for both picture sets. These norms are especially useful in emotion research, because few studies emerge from LMICs, and few instruments account for substantial sociodemographic diversity. Extending the reach of tools such as the IAPS to LMICs can help ensure a more globally representative body of research in this field.