Scientists were shocked to find out that the young goats they were studying had developed distinct "accents" once they began to socialize with other young goats. They used to think that such things were too advanced for mammals, so it was surprising to hear the subtle differences in the way they made sounds.
The way they did it was that they used the same father for 23 young goats, but several mothers. They had them stay with only the mom for a week. They recorded their sounds. Then they made them split into 4 random 'gangs' of 5 to 7 animals, and recorded them again. They realized that each 'gang' had developed their own specific sound!