Unfortunately, there’s never a shortage of examples of men displaying their inability to accept a woman telling them “no” and move on.

These range from the creepy: the man who won’t stop playing the piano in the park until his girlfriend of four months takes him back, to the deadly: the Texas man who killed his wife and seven of her party guests after she filed for divorce. Earlier this year, a man opened fire at a pool party in San Diego because he was “despondent” over his break-up. Mic recently profiled 14 women who were brutally attacked for rejecting the advances of strangers or friends.

And Harvey Weinstein wouldn’t take “no” for an answer. To him, “no” meant “keep trying until you wear her down”; it meant she must not have fully appreciated the immensity of his power and leverage. Ultimately, lack of consent was no imposition.

As a parent, I don’t want to think that any of my three kids—boys ranging in age from 17 months to 9 years old—would ever respond to rejection in such an maladaptive way. But how can I be sure? What should I be doing to teach my sons how to handle rejection? As a society we don’t seem to be doing a very good job at this. TV shows and movies perpetually portray persistence in men as romantic—an initial rejection doesn’t really mean no, it just means try harder and eventually they’ll give in. But no one owes you a “yes” just because you got up the nerve to ask them out on a date. Nor should your identity be entirely wrapped up in your romantic relationship.

So why is it so common for men to struggle with or lash out at a rejection?

“We aren’t giving boys the space to voice emotions as we give to girls,” says Dr. Chris Hafen, a research scientist at the Virginia Adolescent Research Group (VARG) at the University of Virginia. “What that builds is a dynamic where boys are behind girls as far as emotional maturity. So when they come up against a problem that forces them to rely on their emotional toolkit, most of the time that toolkit is inadequate.

Many factors contribute to someone’s potential to react violently to romantic disappointment or relationship failure, but there is one element that appears repeatedly in research: belief in gender stereotypes such as male dominance and poor emotional control. That means it’s important to teach boys healthy ways to express and work out their emotions and reject patriarchal family structures.

If rejection stands to threaten a man’s self-perceived social identity, he may compensate by over-demonstrating his masculinity. Dubbed “masculine discrepancy stress,” CDC researchers reported that men who become stressed because they perceive themselves as less masculine are more prone to violent behavior. Another study found that men who react violently to rejection tend to be less supportive of women’s rights.

These problems start earlier than you might think.

Boys are conditioned to believe they should not display sadness or neediness.

“We start reinforcing these behaviors early in childhood. We’re much more comfortable with boys play-fighting, we encourage girls to be cooperative,” Hafen said. “Then when it comes to romantic encounters, boys sense that they are expected to initiate, they naturally assume they should be the aggressive one.”

So physical aggression may feel more comfortable to boys than say, processing their emotions verbally. Boys are conditioned to believe they should not display sadness or neediness, that that is weak; they are socialized to believe that hostility and aggression are the only manly response.

“When they have frustration, their system for dealing that is aggression. An inability to overcome small conflicts in a relationship can lead to bigger conflicts, and an inadequate ability to deal with rejection,” Hafen said.

According to research out of VARG, learning how to process your emotions and feeling emotionally secure at home as an adolescent have a significant impact on how people behave in adult relationships. Adolescents with stronger emotional repair abilities are increasingly socially competent: their romantic partners report more positive relationships with enhanced communication and fewer critical, blaming, or hostile interactions.

But it’s not just how boys are socialized to be stoic. We know witnessing violence in childhood can lead to people being violent as adults, but more and more research is also connecting the dots on how insecure family attachments in childhood are associated with an increased likelihood of violence against a romantic partner.

VARG has been examining how social relationships and parental attachments affect a child’s development from adolescence into adulthood for nearly 20 years. The group continues to conduct a longitudinal study on 184 early adolescents that began in 1998.

Another one of their studies found that 14-year-olds with “a secure attachment state of mind” were in relationships that displayed more constructive conflict discussion and supportive behaviors at both ages 18 and 21. The researchers note that these results “suggest substantial links between early adolescent attachment state of mind and the adult romantic relationship atmosphere an individual creates and experiences.”

Attachment styles are developed with caregivers in early childhood, and it just means that a child has at least one caregiver they know they can rely on. People who never develop secure attachments can develop rejection sensitivity. People with rejection sensitivity are at a greater risk of perpetuating violence against a romantic partner; some research shows they may be more likely to be the victim of partner violence because out of fear of rejection, they may become more permissive of their partner’s hostility or aggression.

“Certainly a precursor to rejection sensitivity can be insecure attachment issues, but it is not required for developing it,” Hafen said. “Experiencing, say, an embarrassing public break-up in adolescence can trigger someone with secure attachment to develop rejection sensitivity.”

VARG research shows that people with elevated levels of rejection sensitivity at age 16 are less likely to have a romantic partner at age 22, and report more anxiety, avoidance, and negative interactions when they did have relationships.

“They may then pull away from romantic relationships and therefore miss out on the emotional learning experiences that their peers are getting by continuing to date, putting them even further behind,” said Hafen.

The good news? “It’s not an all-or-none situation. Rejection sensitivity isn’t absolutely going to lead to violent outbursts,” Hafen said. “People can find ways to develop healthy relationships, find healthy connections.”

So what’s the best age to start cultivating these important emotional repair abilities? Hafen says if you can start teaching kids emotional intelligence skills in late elementary school, like encouraging them to think more about other people’s emotions, that it can really be really valuable. But at this age, they may not be able to grasp more advanced ideas.

Researchers are finding late middle school/early high school to be a key age. “It seems to be the best time because they are capable of understanding these concepts, if we do it too much earlier, it will go over their head. Too much later, and they may already have established emotional coping patterns,” Hafen said.

Someone’s rejection is not a statement on your self worth or manliness.

VARG is currently developing a curriculum that will be integrated into ninth grade health classes that aims to foster kids’ peer-support abilities, communication skills, and emotional intelligence. This is often an overlooked age. Consent education often doesn’t start until college, and even then only briefly touches on how to proceed when the answer is “no.” We like to think that college romantic relationships are the ones that set our patterns, but the truth is, how we cope with conflict and disappointment is likely established far earlier.

“Once an adolescent develops their coping style, that’s how they’re going to be. The later we go the harder it is. Once your pattern is in place it can be difficult to unlearn,” Hafen said. “If we reach them then, it can have a long-lasting impact. It seems to be a critical age, when there’s a real potential to unlock these abilities.”

So what can caregivers do to ensure their kids develop healthy patterns of coping with rejection?

“The key protective factor, especially when it comes to boys, is that when they struggle with peers or in school—feel rejected from the norm in any way—they need to have parents they can come to who offer supportive dialogue, not judgment,” Hafen said. “What matters is that they have someone close to them that they can open up to and they have a willingness to open up. For boys, it’s the willingness that’s often what’s missing.”

Boys need to be taught that rejection is a part of life, that it’s okay to feel sad about it and to talk about those feelings, but not to take it too personally. If someone doesn’t want to be in a relationship with you, then let them go and move on. Someone’s rejection is not a statement on your self worth or manliness. All children need to be told that their worth is not defined by their relationships, their attractiveness, or the love of another person.