4 April 2000
Facial Expressions are Contagious
by Kate Melville
We meet a smile with a smile, and an angry face with a frown. Facial expressions are very contagious, even on a subconscious level. But is this reaction pure mimicry or a true reflection of an evoked feeling?
New research, which seems to agree with Darwin�s proposition that facial expressions of emotion have a biological basis, has just been published in the journal Psychological Science.
Professor Ulf Dimberg, of Uppsala University, has proposed that expressions are controlled by particular "facial affect programs". Studies of primates show that the evocation of emotional reactions (eg. a threat display) is controlled by innate releasing mechanisms, and is underpinned by specific neurons that selectively respond to facial stimuli.
If human facial expressions are generated by biologically given "affect programs", one would expect these programs to operate automatically by eliciting facial muscle reactions spontaneously and independently of any conscious process. This has been the object for Ulf Dimberg's research at the Department of Psychology at Uppsala University.
In a study conducted on 120 students, Dimberg and his research team measured the facial muscle activity in the zogomatic major (involved in smiling) and the corrugator supercilii (moves the eye brows when frowning) muscles, while the audience was exposed to pictures of happy and angry faces. With the help of a masking technique in combination with a very brief exposure (39 ms), the students were not consciously aware of the exposure.
The study demonstrated that distinct positive and negative facial emotional response patterns could be spontaneously evoked without the awareness of the positive or negative stimuli. The results suggest that the initial facial reactions are controlled by rapidly operating "affect programs" that can be triggered independently of a conscious cognitive process.
This supports the theory that important aspects of emotional face-to-face communication can occur on a subconscious level.
"This is exciting", says Dimberg. "We don't know yet if one should put the greatest emphasis on the biological or the psychological side. One theory is that this unconscious and automatic muscle response to other's expressions can be the first step in a chain reaction, and that it is followed by conscious feeling and actions, such as fleeing from a threat".