Examining affective structure in chickens: valence, intensity, persistence and generalization measured using a Conditioned Place Preference Test.

•Conditioned Place Preference tests were used to study affective responses in hens.•Both air puff and water spray stimuli produced conditioned place aversions.•A robotic snake, and the sound of conspecific alarm calls, did not.•Negative affective responses can differ in their persistence and generalization.