Gentle human interactions trigger positive emotions in chicks

Interaction with humans in early life is known to influence animal behaviour, stress responses, and welfare, but whether animals perceive gentle handling as emotionally positive remains unclear. Here, we used a conditioned place preference paradigm widely used in affective neuroscience but rarely implemented in poultry, to assess whether chicks experience positive emotions when gently handled. Twenty Hy-Line W-80 chicks were tested in a two-chamber apparatus distinguished by colour cues. Following baseline preference assessment, chicks were exposed to conditioning sessions in which chambers were paired with either gentle handling treatment (soft stroking and calm talking) or a neutral human presence (static and silent). Chicks received six 5-min sessions of each treatment across 12 days, on alternating days (one session per day), and colour-treatment pairings were counterbalanced across individuals. Post-conditioning preference was assessed over three consecutive days. Chicks consistently spent more time in the chamber previously associated with gentle handling across test days. Importantly, chicks did not show an aversion to the neutral chamber. These results indicate that gentle human contact acquired positive associative value rather than merely reducing aversion. These findings provide experimental evidence that human-animal interactions can function as rewarding stimuli in poultry, which has implications for husbandry practices and welfare assessment frameworks.