Shared brain activity for aesthetic and moral judgments: implications for the Beauty-is-Good stereotype

Abstract

The Beauty-is-Good stereotype refers to the assumption that attractive people possess sociably desirable personalities and higher moral standards. The existence of this bias suggests that the neural mechanisms for judging facial attractiveness and moral goodness overlap. To investigate this idea, we scanned participants with functional magnetic resonance imaging while they made attractiveness judgments about faces and goodness judgments about hypothetical actions. Activity in the medial orbitofrontal cortex increased as a function of both attractiveness and goodness ratings, whereas activity in the insular cortex decreased with both attractiveness and goodness ratings. Within each of these regions, the activations elicited by attractiveness and goodness judgments were strongly correlated with each other, supporting the idea of similar contributions of each region to both judgments. Moreover, activations in orbitofrontal and insular cortices were negatively correlated with each other, suggesting an opposing relationship between these regions during attractiveness and goodness judgments. These findings have implications for understanding the neural mechanisms of the Beauty-is-Good stereotype.

Fig. 1

Behavioral paradigm. (A) An example in the ‘face attractiveness judgment task’. Female participants were presented with faces of Caucasian young males for 2.5 s each, and judged each face in an attractiveness 8-point scale from very unattractive to very attractive. (B) An example of the ‘action goodness judgment task’. Participants were presented with sentences describing hypothetical actions for 4 s each, and judged each action in a goodness 8-point scale from very bad to very good. (C) An example of the ‘brightness judgment task’, which was used as control task. Subjects were presented with swatches of varying brightness for 2.5 s each and judged each swatch in a brightness 8-point scale from very dark to very bright. In all tasks, trials were separated by a jittered fixation interval (0.5–5 s).

Fig. 2

Results of reaction time data. (A) Participants rated the attractiveness of faces from very unattractive (level 1) to very attractive (level 8). Reaction times in this task showed an inverted-U function indicating greater difficulty for intermediate judgments. (B) Participants rated sentences of hypothetical actions from morally very bad (level 1) to very good (level 8). Reaction times in this task also showed an inverted- U function. All error bars represent standard errors.

Fig. 3

(A) Right medial OFC region where activity increased simply as a function of both attractiveness and goodness ratings. (B) Increase in OFC activity as a function of attractiveness ratings. ‘Low’ corresponds to ratings 1–3, ‘Medium’ to ratings 4–5 and ‘High’ to ratings 6–8. (C) Increase in OFC activity as a function of goodness ratings. ‘Low’, ‘Medium’ and ‘High’ correspond to ratings 1–3, 4–5 and 6–8, respectively. (D) Changes in OFC activity as a function of attractiveness and goodness ratings were highly correlated (r = 0.86, P < 0.01).

Fig. 4

(A) Right insular cortex region where activity decreased as a function of both attractiveness and goodness ratings. (B) Decrease in insular activity as a function of attractiveness ratings. For ratings groupings, see caption of Figure 3. (C) Decrease in insular activity as a function of goodness ratings. For ratings groupings, see caption of Figure 3. (D) Changes in insular activity as a function of attractiveness and goodness ratings were highly correlated (r = 0.78, P < 0.01).

Fig. 5

Significantly negative correlation (r = –0.41, P < 0.01) between right medial OFC activity and right insular cortex activity during attractiveness and goodness ratings tasks. Activations during the attractiveness rating task are plotted in green and activations during the goodness rating task are plotted in brown.