The eyes are sufficient to produce a threat superiority effect.

Abstract
The research described in this article used a visual search task and demonstrated that the eye region alone can produce a threat superiority effect. Indeed, the magnitude of the threat superiority effect did not increase with whole-face, relative to eye-region-only, stimuli. The authors conclude that the configuration of the eyes provides a key signal of threat, which can mediate the search advantage for threat-related facial expressions.
Funding Information
  • Wellcome Trust (064290/Z/ 01/Z)
  • University of Essex (DGPG40)