You may feel lost when you're in a crowd. But CLA life scientists say that being part of a crowd is what makes you unique.
Biologists Kimberly Pollard and Daniel Blumstein examined the evolution of individuality -personal uniqueness - by recording alarm-call vocalizations in eight species of rodents that live in social groups of various sizes.
They found that the size of the groups strongly predicted the individual uniqueness in the animals' voices: The bigger the group, the more unique each animal's voice typically was and the easier it was to tell individuals apart.
The reason, the researchers said, is due to a "Where's Waldo" effect in which it is difficult to pick one individual out of a crowd, and the bigger the crowd, the harder it is.
"But humans and other social creatures can't just give up when crowds get large. We still must be able to identify our friends, our family and our rivals within that crowd," said Pollard, the study's lead author.
The species that had to contend with bigger crowds did so with more unique voices, the researchers found. The larger the social group, the easier it was to tell any two individual animals apart.
"Nature has solved the 'Where's Waldo' problem by endowing highly social creatures with more unique features, which helps them find their pals in the crowd," said Pollard, currently a postdoctoral scholar at the U.S. Army Research Laboratory in Maryland.
And if social species - like humans, for example - were to evolve to consistently live in larger and larger groups, this would likely set the stage for the evolution of even greater individuality, predicted the researchers.
"The number of individuals that humans must recognize seems to be growing, especially as we become more globally connected and as social groups become less clearly defined. This is probably increasing the evolutionary pressure on our own individuality," said Pollard.
"This research helps to explain something that is such a core, critical part of our daily experience - our own uniqueness as individuals," she said. "Our results shed light on the underlying evolutionary reasons why we are all so different."
The research has been published online in the journal Current Biology.