Cheer Lab cheer quiz

A simple quiz: How many members of the Cheer Lab are clearly of good cheer? Base your answer purely on the photos here. These are the members of the Cheer Lab — Joseph Cheer’s lab at the University of Maryland Medical School in Baltimore:

The Cheer Lab is dedicated to “elucidating fundamental neural mechanisms underlying motivated behaviors, and how these are modulated by the recently described endogenous cannabinoid system.” (Thanks to investigator David F. Austin for bringing the Cheer Lab to our attention.)