A year ago, when two-year-old Ana visited her aunt Mary, she started telling her stories as soon as they met. She talked about her recent visit to the market. She talked about school. Then she talked about her little sister.
Ana’s cousin Angel, also two years old, was visiting Aunt Mary too. However, when Aunt Mary asked him “How are you?” he just said “Fine” and turned around to go play. Aunt Mary wondered why Angel wasn’t as talkative.
Should Aunt Mary be concerned? Should she talk to him more? Should she encourage him to talk more? She wondered if there was something she should be doing. Maybe Angel was just “born” that way, and was simply not as expressive as Ana.
This question is at the crux of extensive discussion in the economic literature about sex differences in language acquisition and the development of social skills.
A 2011 study found that girls tend to speak and develop socio-emotional skills earlier than boys. Some scientists claim sex differences result from evolutionary developments and biological processes. That would mean, Aunt Mary should just accept that boys are less expressive than girls. Yet, other scientists have noticed mothers–and many others–use different language for boys and girls. For example, when a toddler asks for something she or he cannot have, it is more likely that mom will say “no” to a boy. However, she is more likely to say “why don’t you try this instead?” to a girl.
Since baby’s brains are “plastic”—meaning that the brain is constantly adapting to what it sees in the world–, this social behavior should result in sex differences. Scientists are well aware that both nature and nurture play a role. However, saying how much each one contributes to the differences is a matter of debate. One would have to observe many instances of boys being spoken to as girls, and girls spoken to as boys, in order to know for sure. Thus, there is no answer for Aunt Mary.
My colleagues, Florencia López-Boo, Xia Li, and I were curious about this topic. Indeed, we are not the only ones. There is rich media coverage on this topic in publications such as the New York Times and The Economist. Thus, we explored sex differences in language and socio-emotional skills in children 7 months to 6 years old in two Latin American countries: Chile and Nicaragua. Our study included almost 21,000 children.
Consistent with studies based on smaller samples, we found females had a significant advantage in both areas in both countries. We were able to confirm for the first time that; sex gaps do exist in young children in large samples in Latin America.
In the study, we also tried to explain these differences in terms of family characteristics, parenting practices, health investments, geographical location and cultural differences. However, we found none of these dimensions explained the gap.
In addition, children this young do not yet act “feminine” or “masculine”; they internalize gender roles later in life. As a result, we ruled out that children were acting out to meet gender expectations when tested. Thus, our evidence supports the idea that Aunt Mary should not worry. Nature may be likely to blame. However, it is also likely Angel will catch up with Ana in his teenage years. Indeed, our study is by no means definite. It just contributes to a wider body of evidence.
This study is interesting not only because it informs people like Aunt Mary. The identification of biological and environmental factors is necessary to inform whether Early Childhood policy should be tailored among gender groups to ensure equality of opportunities.
Today, Ana and Angel are a year older and Ana still talks more to Aunt Mary than Angel does. On their last family visit, Uncle Fernando asked Aunt Mary “Have you noticed Ana talks way more than Angel does? Do you think she will always be that talkative?” “Probably not” responded Aunt Mary as she went to help Grandma take pictures of the kids.
Rosangela Bando is an economics lead specialist at the IDB’s Office of Strategic Planning and Development Effectiveness.
This research is jointly conducted by the IDB’s Office of Strategic Planning and Development Effectiveness and the Division of Social Protection and Health.