Like adults, young children form first impressions by simply looking at the person's face, according to a recent study.

Researchers from Harvard University found children as young as three years old tend to judge an individual's character traits, such as trustworthiness and competence, based on physical features. They shows that the predisposition to judge others based on their looks starts early in childhood and does not require years of social experience.

"If adult-child agreement in face-to-trait inferences emerges gradually across development, one might infer that these inferences require prolonged social experience to reach an adultlike state," Cogsdill and colleagues write. "If instead young children's inferences are like those of adults, this would indicate that face-to-trait character inferences are a fundamental social cognitive capacity that emerges early in life."

For the study, researchers examined 141 children between the ages of 3 and 10 and 99 adults. They had the study participants evaluate pairs of computer-generated faces that differed on one of three traits: trustworthiness (i.e., mean/nice), dominance (i.e., strong/not strong), and competence (i.e., smart/not smart).

When asked to judge "which one of the people is very nice," adults and children attributed traits based on physical appearances.

"If such inferences take root early in development, as the data suggest, even infants might associate faces with trait-consistent behaviors, such as those conveying prosociality," the researchers note.

It is still unclear exactly when the tendency to infer character from faces first emerges, "it might be possible to test younger children with the same computer-generated faces to find out," researchers said.

The study was published in Psychological Science, a journal of the Association for Psychological Science.