The augment effect of negative affective background on positive stimulus: Two randomized controlled trials

Based on the affective endowment-contrast theory, negative affect (NA) is hypothesized to augment positive affect (PA). Study 1 examined this contrast effect (augment effect) in a laboratory setting. Participants (n?=?94) were assigned into positive, negative or neutral affective background conditions through false feedback procedure, and then a same positive stimulus was given to all participants. Results indicated that participants in negative condition experienced more feelings of PA and less NA after receiving the positive stimulus compared to the other two conditions. Study 2 investigated this augment effect under naturalistic context. Participants (n?=?150) were classified into high positive, high negative, or mild positive affective background groups based on their naturally occurred affects. Then a positive manipulation was giving to all participants. Results indicated that participants in the high negative group experienced the most decrease in feelings of NA after receiving the positive manipulation. Results from the two studies provided evidence to the endowment-contrast theory, indicating that the valance of positive stimulus was augmented under negative affective background.