No Evidence for Emotional Empathy in Chickens Observing Familiar Adult Conspecifics Edgar, Joanne L. ; Paul, Elizabeth S. ; Harris, Lauren ; Penturn, Sarah ; Nicol, Christine J. Abstract Publication: PLoS ONE Pub Date: February 2012 DOI: 10.1371/journal.pone.0031542 Bibcode: 2012PLoSO...731542E