As Oscar Pistorius waits to fight the murder charge against him following the shooting death of his girlfriend, Reeva Steenkamp, allegations continue to surface that the Blade Runner was a man prone to violence. If it’s true that the star of the 2012 Olympics had abusive tendencies, it raises a question: why did Steenkamp stay? For that matter, why does any woman remain in a relationship where her physical or emotional safety is threatened? Why did Rihanna choose to go back to Chris Brown after he beat her?

There’s no straightforward answer, and every situation is unique. But there are common contributing factors that may help explain why women don’t leave or feel they can’t. One of those underlying determinants, and one that’s often overlooked, is the lasting influence of early traumatic life experiences, according to Vancouver doctor and author Gabor Maté.

“It’s perfectly true that in girls who are stressed around age four, for example, that stress will mean higher levels of the stress hormone cortisol in their bodies and their brains, and the results show up on brain scans 14 years later,” Maté says in a phone interview. “These girls are more anxious and depressed [than those not exposed to such turmoil]. It also means less capacity to handle stress and more of a tendency to get into stressful situations without recognizing them because they’re so used to it. They’re drawn to stress.”

Maté, whose books include When the Body Says No: The Cost of Hidden Stress and In the Realm of Hungry Ghosts: Close Encounters With Addiction, argues that physiological and psychological development is heavily dependent on the nurturing environment that exists in a person’s first few years of life. Children’s emotional and psychological surroundings shape their brain development in crucial ways.

That’s not to say that every woman who’s in an abusive relationship experienced abuse as a child, of course. However, he maintains that in today’s stressed-out society, any sustained emotional disconnection with a parenting figure—which can happen when a parent is excessively worried or preoccupied over a long period—can have a lasting, detrimental impact. And he contends that many people carry with them pain from childhood, even if it didn’t result from severe neglect or abuse.

In his books and on his website, Maté refers to the Adverse Childhood Experiences study, which involved 17,000 participants. The U.S.–based Centers for Disease Control and Prevention research (which is ongoing) found that adversity in childhood causes mental-health disorders such as depression, hallucinations, and posttraumatic stress disorders. The more categories of trauma experienced in childhood, the greater the likelihood of experiencing everything from ischemic heart disease and liver disease to sexually transmitted illnesses—as well as risk for intimate-partner violence.

“When you’re traumatized early [in life], a child can’t help but take that personally,” Maté says. “They’ll think, ‘If this bad thing happened to me, there’s something wrong with me.’ Girls especially are socialized to think that that’s what they deserved and gravitate to men who will be abusive. When you think about it, whose love did they most want? Very often it’s [that of] the abusive male. When they sense abusive potential in a male, they’re more likely to fall in love with it not because they recognize danger but because it resonates with the love they always wanted.

“I see it all the time,” adds Maté, who used to work in the Downtown Eastside as well as in palliative care and who now speaks internationally and conducts healing retreats to help people overcome trauma and addiction. “That early stuff is responsible for just about everything we do as adults in ways we’re not conscious of. The whole process of self-liberation is to let go of those early patterns and become who you truly are before you were ingrained with those patterns. So the woman who liberated herself from that abusive pattern essentially goes back to being her true self; all that other stuff was just programming, but it’s very powerful programming and it’s very difficult to escape from. They [women in abusive relationships] feel isolated and alone and ashamed.”

Jocelyn Coupal, a Vancouver lawyer and domestic-violence-prevention advocate, says that men who witnessed parental violence as kids are three times more likely to become abusers themselves. Men who routinely intimidate, threaten, or assault other people will sooner or later turn this abuse on their partners. Plus, she says research indicates that men who are verbally abusive are likely to become physically violent against their partners.

“People with a history of violence are much more likely to engage in future violence,” she says. “What did Rihanna tell Oprah about her background and Chris’s background? They came from abusive homes, both of them, where their fathers were abusive to their moms.”

Coupal notes that women and their children who have help from friends, neighbours, family members, and coworkers are more likely to get out of an abusive relationship safely than those who don’t have such aid. Matters are more difficult when an abused woman has additional challenges, such as disability, addiction, poverty, pregnancy, mental illness, and literacy issues.

There are cases where the abuser interferes with immigration status (threatens to revoke sponsorship, for instance), the woman’s ability to work, and custody or control of any children, or threatens to withhold a woman’s passport or legal documents. (Coupal’s website, spotthesigns.ca, includes information on resources for women in a violent relationship and for people concerned about someone in such a situation.)

When an abuser exhibits obsession, jealousy, control, and coercion, the potential for violence often escalates after the abused woman leaves the relationship. Separating from a violent partner, in fact, is the most common risk factor for domestic homicide.

“The most dangerous thing an abused woman can do is leave without a safety plan,” Coupal says in a phone interview. “If you leave, they are going to try to get you back and they will do whatever they can to achieve that end.”