Vol. 7, Issue 1, Part E (2025)

This study examines high sensitivity (HS) in canine units of the Spanish State Security Forces, assessing its psychological, operational, and decision-making impact. A mixed-methods design combined HS screening in handlers and dogs with a qualitative phase of 13 in-depth interviews, coded into 23 categories and analysed through co-occurrence, Jaccard index, and prosodic analysis on a subsample of 11 audio recordings. Results depict a pattern of multisensory hyper-reactivity, fast learning, high correction sensitivity, and strong emotional attunement to the handler. Performance follows a biphasic pattern vulnerable to overstimulation but outstanding when management is aligned with the dog’s sensory threshold. The handler’s perception of HS emerges as a critical factor shaping the entire operational cycle: from puppy selection and potential identification to role assignment, performance evaluation, and adult dog dismissal. The institutional stigmatisation of sensitivity and fear fosters misinterpretations that lead to the loss of high-potential animals. We conclude HS is a modifiable operational trait and propose incorporating psychological, sensory, and behavioural indicators into selection and training, complemented by lexical-semantic and prosodic metrics as diagnostic tools when classical tests are unsuitable for specialised populations.