We designed two experiments, the one for NEUTRAL messages and another one for affective messages, but merged them into one online study when we collected data.
For the NEUTRAL message experiment, we conducted a two-by-two factorial design with one baseline comparison, where the effect of the “facial expression” (positive/negative) and “animation” factors (animated/static) on receivers’ perception were compared. The five conditions, including
“Pos-Animated-PP”,
“Neg-Animated-PP”,
“Pos-Static-PP”,
“Neg-Static-PP”, and
“Neutral-Static-PP”.
PP denotes “profile picture”. We showed participants NEUTRAL messages accompanied by an animated happy face, an animated angry face, a static happy face, a static angry face, and a static neutral face, respectively (Figure
4, left side). We used happy and angry facial expressions because they have the highest arousal in positive and negative valence according to Russell’s circumplex model [
61] and they were also commonly used to represent positive and negative emotions in related works (see [
13,
36]).
For the affective message experiment, we also conducted a two-by-two factorial design with one baseline comparison, where the effect of the “facial expression” (congruent/incongruent) and “animation” factors (animated/static) of profile pictures on receivers’ perception were compared. The emotion of the facial expression in each condition was also decided based on Russell’s circumplex model [
61]. We selected emotions that display similar arousal levels but with opposite valence in order to control the potential influence of arousal levels. For instance, happy and angry are categorized as high arousal, where happy is positive-valenced while angry is negative-valenced. Therefore, we paired an happy face with HAPPY messages for congruent condition, whereas we paired an angry face with HAPPY messages for incongruent condition. There were five conditions,
“Congruent-Animated-PP”, “Incongruent-Animated-PP”, “Congruent-Static-PP”, “Incongruent-Static-PP” and
“Neutral-Static-PP”. In the
Congruent-Animated-PP condition, we paired an animated happy facial expression with happy messages, an animated relaxed facial expression with relaxed messages, an animated angry facial expression with angry messages, and an animated sad facial expression with sad messages. In the
Incongruent-Animated-PP condition, we paired an animated angry facial expression with happy messages, an animated sad facial expression with relaxed messages, an animated happy facial expression with angry messages, and an animated relaxed facial expression with sad messages. In the
Congruent-Static-PP condition, we paired a static happy facial expression with happy messages, a static relaxed facial expression with relaxed messages, a static angry facial expression with angry messages, and a static sad facial expression with sad messages. In the
Incongruent-Static-PP condition, we paired a static angry facial expression with happy messages, a static sad facial expression with relaxed messages, a static happy facial expression with angry messages, and a static relaxed facial expression with sad messages. In the
Neutral-Static-PP conditions, which served as a baseline comparison, we paired a static neutral facial expression with HAPPY, RELAXED, ANGRY, and SAD messages (Figure
4, left side).
We examined the effects of these two factors on NEUTRAL, POSITIVE (HAPPY and RELAXED), and NEGATIVE (ANGRY and SAD) messages. Notably, we did not compare across messages; thus, they were not considered a factor.