The First Circuit has ruled on the legal inference that may permissibly be drawn from yawning.
In Arroyo-Audifred v. Verizon Wireless, Inc., the plaintiff alleged that his employer discriminated against him on the basis of age in violation of the Age Discrimination in Employment Act. Verizon explained that it did not promote Arroyo-Audifred despite his numerous attempts to advance in the company because he was not "professionally mature," and because other employees were better suited for the jobs he sought. Arroyo-Audifred claimed that he never had a chance for a promotion because of Verizon's discrimination against him based on his age.
The proof? During a job interview for a better job, the manager conducting the interview yawned. Arroyo-Audifred argued that the manager's yawn in this context indicated that Arroyo-Audifred's responses to questions did not matter; the decision not to promote him based on unlawful discriminatory reasons had already been made.
The First Circuit on appeal from D. Puerto Rico affirmed summary judgment for Verizon. "While we agree that such an act [the interviewer's yawn] could make an interview awkward, we fail to see how an involuntary yawn evinces a hidden discriminatory animus any more than a sneeze or a cough."