New Delhi, July 25 -- Smartphones are influencing how children under 13, especially girls, think and develop, and experts have warned that this early exposure could lead to poorer mental health outcomes later in life.

One of the study's authors, Tara Thiagarajan, said that more exposure to smartphones impacts younger children psychologically and alters the way they think and perceive the world.

"The younger the child gets a smartphone, the more exposure to all this impacts them psychologically and shapes the way they think and view the world," she told ABC News.

The study, published in the Journal of Human Development and Capabilities, analysed self-reported questionnaire results from more than 1,00,000 young adults between the ages of...