"We tested participants in four age groups: 6 years old, 8 years old, 10 years old and adults (over 18 years) as a control group. In each age group there were 1

"We tested participants in four age groups: 6 years old, 8 years old, 10 years old and adults (over 18 years) as a control group. In each age group there were 10 participants who had a family dog in the household and 10 who never had one. The 6-year-old group was tested in kindergartens, the 8 and 10-year-old groups were tested in elementary schools. The adult group was recruited from university students. The sex ratios of each group were balanced. The mean ages of dog-owner and non-dog-owner adults were 23.80 ± 1.33 and 24.10 ± 3.19 years, respectively." And the dogs: "Barks from the Mudi breed (a Hungarian sheepdog listed at the 238th Standard of the FCI (Fédération Cynologique International)) were used for this study. We recorded bark samples from eight adult individuals (male/female: 3/5, age: 4.13 ± 2.30 years)." Keep in mind its some ethnologists from a Hungarian university. It's not like they will have huge funding.