Teens using e-cigarettes are more likely to take up smoking, a study by the University of Southern California showed. The study also found that youngsters have a positive attitude toward e-cigarettes if they are used by their friends and family.

Researchers conducted the study on 2,084 teens studying in 11th and 12th grades in Southern California. They found that 24 percent admitted to using an e-cigarette at least once, 9.6 percent were current e-cigarette users, and 18.7 percent had smoked a traditional cigarette.

About half of the participants of the study, published Monday in the journal Pediatrics, said they believed that e-cigarettes were harmless. 

“While it is possible that some adolescents are using e-cigarettes instead of cigarettes, our data suggest that e-cigarettes may be recruiting new tobacco product users who might not have used cigarettes,” Jessica Barrington-Trimis, lead author of the study and a professor in the department of preventive medicine at the University of Southern California, said, according to Forbes.

Researchers found that psychosocial factors such as the use of e-cigarettes and tobacco cigarettes by family and friends had an impact on the participants’ use. However, they did not find any causal link between e-cigarette use and traditional cigarette smoking among teens.

"E-cigarettes often contain nicotine, so they may induce sort of a psychological dependency on nicotine and then may lead to future cigarette use," Barrington-Trimis told NBC News' Today. "Or, e-cigarettes may lead to the normalization of smoking behaviors and that's the normalization that we're concerned with."

The study team said that further studies are required to determine whether the strong association between psychosocial factors and the use of e-cigarettes will act as a gateway to tobacco abuse.