Look at me, I'm smiling: Visual search for threatening and nonthreatening facial expressions

Using a visual search paradigm, this series of experiments determined whether threatening and nonthreatening facial expressions attract attention. In Experiment 1, participants were instructed to locate a face with a particular facial expression in an array of four or eight faces. Search time was reduced for a happy target among neutral distractors, compared with a neutral target among happy distractors. In contrast, when the stimuli were inverted, search time was faster when the target was neutral and slower when the target was happy. An increase in the number of distractors increased search times to a greater extent when the target face was neutral and inverted than in the other conditions. Experiment 2 revealed the same pattern of results for sad faces. Experiment 3 used a modified search array to directly compare search times for happy, sad, fearful, and angry facial expressions. The attentional advantage for happy and sad targets shown in Experiments 1 and 2 was examined further by comparing search times when participants were instructed to search for a particular expression with those obtained when they searched for any emotional expression. Angry and happy targets were located faster than sad or fearful faces, and at least part of this advantage was determined by task instructions rather than being automatic. These findings demonstrate that nonthreatening facial expressions (happy, sad) can capture attention relative to neutral expressions, and that threatening expressions differ in their effect. It is suggested that angry faces indicate potential threat to the observer (e.g., the threat of personal violence) and therefore attract attention, whereas fearful faces indicate threat elsewhere in the environment (e.g., the approach of a violent intruder), and therefore divert attention away from the face and towards the source of the threat.