How ADHD-like traits and training affect dogs' self-control

Abstract

Self-control is crucial for family dogs in an anthropogenic environment. As valid models of Attention Deficit Hyperactivity Disorder (ADHD), dogs may show behavioural inhibition impairments similar to those seen in humans. This study examines links between dogs' ADHD-like traits and their ability to delay gratification (DG) - a key aspect of self-control impaired in children with ADHD. We tested N = 50 family dogs using an intertemporal choice task, where dogs chose between an immediate low-value reward and a delayed high-value reward. Dogs completed 20 delay trials, with delays increasing by 1 s upon successful waiting. The maximum delay reached and waiting behaviour during successful trials were recorded. ADHD scores were obtained from a validated owner-report questionnaire, and training level was included in the analyses. Higher total ADHD scores were associated with shorter maximum delays, but only in dogs with basic or intermediate training. Inattention scores were negatively linked to DG performance in dogs with basic/intermediate training, while hyperactivity was associated with poorer DG only in dogs with basic training. Impulsivity scores were not linked to success. Although some behavioural consistency was observed during waiting, limited between-individual variation prevented the identification of links with success or ADHD-like traits. Our findings mirror human research, showing links between inattention, hyperactivity, and self-control deficits, supporting dogs' potential as a model to study human ADHD. The lack of association with impulsivity suggests the domain-specificity of this trait. The role of training level highlights its importance as a moderating factor in behavioural studies of self-control.