The Truth about Dogs Repository

A curated, evidence-led repository on humane, force-free dog training — peer-reviewed studies, official positions, and expert voices, with sources you can check.

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Peer-reviewed2020Open access

Dogs from aversive schools showed more stress and more pessimistic outlooks

A quasi-experimental study of 92 companion dogs compared training schools and found dogs from aversive schools showed more stress behaviour, higher cortisol increases, and more pessimistic judgements in a cognitive-bias task.

Dogs trained with aversive-based methods experienced poorer welfare as compared to those trained with reward-based methods.

Source details

Source

Does training method matter? Evidence for the negative impact of aversive training methods on companion dog welfare

Vieira de Castro et al.

PLOS ONE

Evidence level

Primary evidence

Credibility

Last reviewed

May 30, 2026

Why we included it

One of the strongest welfare studies in the field — measures both immediate stress and longer-term affective state via cognitive bias.

WelfareReactivityGeneral