William Bukowski, a professor of psychology at Concordia University in Montreal, and colleagues analyzed responses from children in Montreal and in Barranquilla, a city on the Caribbean coast of northern Colombia.
The researchers studied the responses of 864 early adolescents age 9-11, 317 from Montreal and 547 from Barranquilla. The numbers of boys and girls, and the socioeconomic classes they represented -- upper-middle and lower-middle -- were roughly equal.
Overall, the study, published in the Journal of Research on Adolescence, found no differences between the participants from the two cities, which they said was somewhat of a surprise.
However, there were differences among classes.
"Children from upper-middle-class families were likely to consider social skills as the most important factor when evaluating themselves," Bukowski said in a statement. "If they felt they were popular or likeable, they were more likely to have high self-esteem. While they did consider their athletic and intellectual abilities, they seem to have understood that social skills are crucial for success among individuals of their class."
On the other hand, children from lower-middle-class families focused on evidence of their cognitive competence when assessing themselves to determine their self-worth. If they believed they were smart and successful at school, they were more likely to have healthy self-esteem, the study said.