Page 76 - Emotions through the eyes of our closest living relatives- Exploring attentional and behavioral mechanisms

Chapter 3
(t(11.03) = 3.76, p < .001), distress (t(11.03) = 8.24, p < .001) and yawning (t(11.03) = 7.68, p < .001) more intensely from scenes showing bonobos rather than humans. A final set of comparisons showed that almost all emotion categories were perceived as more intense than neutral (ps < .003) except self-scratching bonobos (perceived by adults p = .77 with an opposite effect in children p = .003), and in children, self-scratching humans (p = .085) or grooming humans (p = .933).
Finally, there was a three-way interaction between Sex, Emotion Category and Species (F(5, 11.03) = 5.69, p < .001). Follow-up tests revealed that compared to men, women gave higher arousal ratings for the following bonobo scenes: grooming (t(11.03) = 6.47, p < .001), yawning (t(11.03) = 4.09, p < .001), play (t(11.03) = 3.01, p = .003), neutral (t(11.03) = 3.75, p < .001) and the following human scenes: distress (t(11.03) = 4.57, p = .002), yawning (t(11.03) = 2.92, p = .004 and neutral t(11.03) = 2.91, p < .001). Also, while both males and females gave higher intensity ratings following yawning bonobos versus humans (males t(11.03) = 7.14, p < .001; females t(11.03) = 6.57, p < .001) and lower ratings following neutral bonobos versus humans (males: t(11.03) = 4.72, p < .001; females: t(11.031) = 6.10, p < .001), males also gave higher ratings following distressed bonobos versus humans (t(11.03) = 4.81, p < .001) and lower ratings following grooming t(11.03) = 3.79, p < .001 and playing t(11.03) = 2.33, p < .001) bonobos versus humans. Although both males and females generally gave higher arousal ratings to the emotional scenes compared to the neutral ones, this pattern was a bit stronger in men. In men, this was significant for all categories (ps ≤ .001) except self-scratch (bonobo scenes: p = .045; human scenes p = .466) and human yawns (p = .082). In women, apart from generally perceived higher intensity from the emotional compared to neutral scenes (ps ≤ .001), no differences were found in the category self-scratch (bonobo scenes: p = .036; human scenes p = .490), and of the human scenes the categories grooming (p = .225) and yawn (p = .850).
In a second analysis, we focused on human adults, adding the category Sex, since children did not have this category. Within the adult sample, the main effect of Emotion Category remained significant (F(1, 10.13) = 289.23, p < .001) with the ordering of the categories almost being identical as before, except that the category Sex received the most positive rating of all. The earlier observed main effect of Species was maintained, showing higher ratings for the human scenes (F(1, 9.52) = 289.23, p < .001). Similarly, the gender difference was maintained as well (F(1, 10.13) = 22.71, p < .001). The interaction between Emotion Category and Species was also maintained (F(6, 10.13) = 28.50, p < .001), and the interpretation was the same.
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