March 21, 2013
Emma Cohen and Daniel Haun report the results of two studies conducted in four rural towns in the Brazilian Amazon (Mato Grosso and Pará states). Two of the towns have a single dominant accent and two of the towns have a variety of accents. The multi-accent towns are relatively new towns, having been established from the 1960s through government incentives offered to prospective migrant landowners across the country. The towns continue to attract newcomers, maintaining accent variation through the generations. This ‘natural lab’ allowed the researchers to investigate how everyday exposure to different accents influences children’s sensitivity to accent in decisions about friendship and cooperation.
Images of identical puppets
In the first study, participants chose between two individuals presented as still images of identical puppets on a computer screen. One individual spoke with a native local accent (or, in the case of multi-accent towns, with the accent that matched that of the participant) and the other individual spoke with an unfamiliar native Madeiran accent. The researchers found that children preferred the puppet who spoke with the local accent as a friend (“who would you like to be friends with?”).
In another trial, children had the option of gaining a sweet and giving one sweet to either the local-accented individual or the unfamiliar-accented individual. Again, children also preferred to share with the local-accent puppet. However, the local-accent preference also had its limits. In a third kind of trial, children chose between gaining one sweet and giving one to the local-accented individual or gaining two sweets and giving one to the unfamiliar-accented individual. In other words, sharing with the local-accent puppet came at a cost. Whereas children showed a local-accent preference provided that there was no cost to self, on costly trials children showed no such preference. Rather, children preferred the option where they got two sweets and the non-local accented speaker received one. “Taking these results together”, Cohen explains, “we see a local-accent preference where distributions are equal, as well as a preference for more sweets for self”.

Subtle differences between accents
A comparison of preferences across the four Brazilian towns revealed that preferences for the local-accented speaker were strongest in multi-accent towns. Only children from multi-accent environments showed a significant preference for the local-accented speaker. “This raises the question of whether children in the multi-accent sites more readily perceive the differences between accents,” says Cohen. “Perhaps the children in the mono-accent sites do not perceive the subtle differences between the regional accents used and therefore show no significant social preferences.”
Discriminate among accents
In the second study, Cohen and Haun investigated the ability of a separate group of children from the same towns to discriminate among accents. They found that children from the multi-accent sites were better at discriminating the local from the non-local accent than were children from the mono-accent sites. “This suggests that participants from multi-accented sites have a better-tuned ear for accent variation. This may, in part, account for the different social-preference effects found across the site types,” says Haun.
The research sheds light on the mechanisms that guide cooperation and their development in children across different ecological contexts. Accent is a universal, ancient, hard-to-fake, and highly salient marker of social identity. Some researchers think it had an important role in the evolution of cooperation in humans, guiding people's decisions about who they could trust and cooperate with.
Cohen summarises: “The preferences revealed here suggest that even young children use accent when making decisions about who to befriend and share with. We also observed, however, that the preference for similar-accented speakers is not so strong as to override the preference for an extra treat. We were particularly interested to find that the social and linguistic environment in which children grow up appears to influence their ability to discriminate among accents."
"In the future," she continues, "we'd like to look at how children across the sites respond to familiar local and familiar non-local accents – presumably, children in both kinds of site will be able to distinguish familiar varieties, but will they pay attention to these differences in the same way? We're also keen to find out whether accent is special – how does it compare to the other hard-to-fake and hard-to-hide identity markers known to guide children's social preferences, such as race? Brazil offers excellent opportunities to build on this initial research and to answer important questions about the roots of both discrimination and cooperation."