Kevin Kozicki/Image Source/Getty Images Dogs with certain kinds of behavioural problems are more likely to show improvement during training if their owners are extroverts and open-minded. After comparing human personalities and the success of behavioural training, scientists have found that introversion, close-mindedness and even conscientiousness are linked to fewer changes in some types of undesirable dog behaviour, including aggression and fearfulness. Advertisement The information could help veterinarians identify dog-owner pairs that might need more help during training, says Lauren Powell at the University of Pennsylvania School of Veterinary Medicine, who co-led the study. Over a six-month period, Powell and her colleagues followed 131 dogs and their owners attending training sessions with a University of Pennsylvania veterinarian, who performed an initial behaviour assessment of each dog. The dogs had various issues, such as aggression towards people or dogs, chasing cars or animals, general fearfulness, separation anxiety, excessive barking and fear of being touched.