Individuals who are low in agreeableness are typically less concerned with others'' well-being and may be suspicious, unfriendly and competitive.
However, the study found no association between liking an aggressive dog and delinquent behaviour, or the possibility that liking an aggressive dog is an act of ''status display'' to show off or attract romantic partners.
"This type of study is important, as it shows assumptions are not the whole picture. It is assumed owners of aggressive dogs (or dogs perceived as aggressive) are antisocial show-offs. But we did not find persons who expressed a preference for aggressive dogs had committed more delinquent acts, or reported showing off more," said Vincent Egan, lead researcher on the study.
"However, we did find a preference for a dog with an aggressive reputation was related to being younger and being lower in agreeableness (i.e., being less concerned with the needs of others, and being quicker to become hostile)," he said.
Elaborating more on this Egan revealed that the study looked at the reasons why some people prefer aggressive dog breeds.
"A lot of human behaviour involves status display and dominance, and evolutionarily this helps with finding mates. Basic personality also influences a lot of our behaviour. By measuring both at the same time, we could see whether they each had an influence on liking aggressive dogs, or whether one was due to another.
"We were surprised mating effort did not have an influence here, but think it might be because we looked at a wider age range. A preference for a non-aggressive dog may also make a statement about a person; liking a pedigree Labrador or a clipped Poodle may be as much a statement as having a pit-bull with a studded collar," he said.
For the study, participants indicated their preference for different types of dogs, and filled in the personality tests.
On the other hand, the dogs were independently rated according to how aggressive people perceived them to be.
Bull terriers were rated as most aggressive, followed by boxers; retrievers and cocker spaniels were seen as least aggressive.
After analysing of the findings, the research team found that certain personality factors indicated a preference for dogs perceived to be more aggressive.
Low agreeableness and higher conscientiousness were linked to a preference for aggressive dog breeds.
Moreover, younger people were also more likely to prefer the aggressive breeds.
Surprisingly, the results indicated a small effect suggesting that those who liked aggressive dogs showed signs of conscientiousness and other personality characteristics such as being careful, reliable and thoughtful about their actions.
This contradicts the perception that owners of aggressive dogs are always irresponsible.
"These results with Conscientiousness were unexpected, but the effect is a small one, and needs to be repeated in a different group of people. Studies of this kind tend to only look at a restricted age ranges, which may exaggerate findings which do not occur across the entire lifespan, so we believe a stereotype is always true, whereas it may only be true under certain conditions. Our study employed a broader age range.
"We were surprised to find a small association between a preference for aggressive dogs and greater Conscientiousness (i.e., valuing and following rules). However, dogs also prefer rules and firm boundaries themselves. We speculate that cheap dog-training classes would be enjoyable and beneficial for both dog and owner," Egan added.