facepalm

Facepalm is a gesture in which an individual places the palm of one or both hands on their face to express one of a number of emotions, including shock, disbelief, distress, embarrassment, horror and frustration. The eyes are covered and/or closed and the gesture may also include a forward movement of the head, sinking the face into the hand or hands. 

The facepalm position and others in which people's hands partially cover their faces are known as facial occlusion poses. These positions are problematic for facial recognition software because an individual's hands and face share a number of characteristics, including skin tone and texture.  

People often use their hands in conjunction with their faces to convey emotions. The interpretation of body language is central to areas like gesture recognition and relevant to marketing, software design, robotics and artificial intelligence (AI). Current efforts to make such information available to software systems include creating standardized interpretations of various facial occlusion poses and encoding that information.  

The word facepalm was not reported prior to this century. According to some sources, the earliest reference is from 2001, while others cite 2006. However, the gesture dates back (at least) hundreds of years. The image here, of a statue by sculptor Henri Vidal, depicts Cain's facepalm after he killed his brother Abel. The facepalm position has also been observed in non-human primates.