(CNN) Sexting among teens and younger children has increased over the past decade and poses a growing challenge for educators and parents, according to a new study .

One in four young people said they'd received sexts, and one in seven reported sending them, according to the study, which was published Monday in the journal JAMA Pediatrics. The research included data from 39 separate research projects conducted between January 1990 and June 2016, with a total of 110,380 participants, all of whom were under 18 -- with some as young as 11.

The researchers focused on data since 2008 and found an increase in sexting among young people.

The increased number of young people involved in sending or receiving sexually explicit photographs or messages has corresponded with rapidly expanding access to cell phones.

With that trend in mind, the study's authors suggest that "age specific information on sexting and its potential consequences should regularly be provided as a component of sex education."

Why sext?

The researchers found that younger people engage in sexting in large part as a way to begin exploring attraction to other people.

"As teens get older, we are going to see increasing numbers ... who sext. Just as we see with actual sexual behavior," said study co-author Jeff Temple, a professor of psychiatry at the University of Texas Medical Branch.

"It's not terribly surprising considering as teens age, their interest in sexuality is heightened. They are trying to figure out who they are."

Kami Kosenko, a communications professor at North Carolina State University, agreed: "As individuals become more comfortable talking about sex and interact with more potential sexual partners, we would expect to see them engage in more sexual communication, of which sexting is a part." Kosenko was not directly involved in the study.

Teens sometimes 'assume safety'

The study predicts a similar upward trend in sexting among younger teens and preteens. Coupled with a lack of awareness of the risks involved, especially among younger children, that is a cause for concern, the researchers said.

Preteens can be particularly vulnerable to the pitfalls of sexting. Relationships among tweens (children 10 to 12) are often short-lived, and that makes individuals more vulnerable to having sexts forwarded without consent or being subject to sextortion: the use of nude images and or videos as a form of threat or blackmail.

"As tweens and kid smartphone ownership gets younger and younger, we are going to see an increase in the number of teens who are sexting," Temple said.

On average, children in the study were 10.3 years old when they got their first smartphones.

Danger also arises from messaging apps that give the impression that videos and images shared or stored are private, although this may not be the case.

"Teens can sometimes assume safety or security is embedded in these apps when it's not," said study co-author Sheri Madigan, an assistant professor in the Department of Psychology at the University of Calgary.

"Kids don't really have a clear understanding of cause and effect," Madigan said. "When they send a picture, they may not recognize they cant get it back or that it is really up to the recipient to decide how they are going to treat that picture."

Kosenko said that "with youth acquiring cell phones at younger and younger ages, we should be concerned about their digital and physical safety."

Part of the problem lies in the children's brains, Madigan said. "Younger teens who have less developed frontal lobes are less able to think through things than older teens. They are likely more vulnerable to being coerced into sexting or to participate in nonconsensual sexting."

There is little or no literature on tweens and sexting, according to Madigan, who suggests that it is important to do further research on the topic.

Nonconsensual sexting

According to the study, 12.5% of young people -- or one out of every eight -- report that they have been forwarded a sext without consent from the sender and/or the receiver.

"That is why this concept of digital safety and security is so important: because we know that this is happening. We know that sexts are being forwarded without consent, so if parents are having conversations with their teens about sexting, they can talk about those potential risks," Madigan said.

Nonconsensual sexting can take a toll on a teen's health.

"If we look at things like sexual behavior with teens, if it's consensual and both teens wanted it and are OK with it, you are not going to see the negative psychological health. If it was nonconsensual or coerced, that is where you see the negative mental health problems, and we see the same thing with sexting," Temple said.

According to the study, further research needs to be conducted on nonconsensual sexting "to appropriately target and inform intervention, education, and policy efforts."

What parents need to know

JAMA Pediatrics defines sexting as "the sending or receiving of nude or seminude images or sexually explicit text messages." This can happen voluntarily in a relationship or when a teenager is asked to "prove" how much they like someone. It can also happen without consent.

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The biggest concern, according to the journal, is the possibility of photos or messages being spread to other people. Sexting can cause severe emotional distress, which is why it is important to talk with children about it. The researchers suggest:

Start the discussion early with your kids using broad questions such as "have you heard of sexting?" By understanding what your child already knows, you can then frame your conversation.

Use examples appropriate for your child's age. Be specific about the possible consequences of sexting. "Parents should be proactive and not reactive," Madigan said.

Remind your teenager of their own worth. Let them know that being pressured is not OK and that sexting is not a way to "prove" their love. "If you have the conversation early and often, when problems arise, then kids know they can go to their parents and talk to them," Madigan said.

Being open and withholding judgment are keys to a successful interaction with a young person about sexting, Kosenko said.

"This means that demonizing sexting won't work. Also, don't assume that you are the expert on the subject or the one who should lead the discussion," she said.

"You might be tempted to tell your children to ask you if they have questions, but consider what can be gained by letting your children tell you what they know and think about sexting."