Nosing through your partner’s smartphone could reflect whether or not your relationship is headed downhill, according to new research presented earlier this year.

To find out the motivation behind snooping, the researchers asked more than 100 people to share a time when they either snooped through a close contact's phone or someone they knew had gone through theirs. Participants in Europe, Canada, and the US were asked in an online survey to describe events leading up to the snooping incident, how it was conducted, and what happened afterward. Of those who gave personal anecdotes, 45 percent said the relationship – friendship, romantic, or otherwise – eventually ended, while 55 percent said they made it through.

“In cases where the relationship ended, it was either because the phone owner felt their trust was betrayed or the relationship was also experiencing difficulties,” said study author Ivan Beschastnikh, a professor of computer science at UBC, in a statement. “Another main reason was the relationship was not that strong or important to begin with, as was the case with two work friends where one stole valuable contact information from the other’s cellphone.”

Researchers further categorized respondents into two separate groups: Those who understand trust as a vulnerability and believe it needs to be built up over time and is necessary to sustain a relationship. Second, those that blame the circumstances and the other person but don’t look to themselves for understanding why their partner may have snooped in the first place. When a relationship was seen as solid, the victim said they were able to overlook the offense because they deemed the relationship more important than the violation of privacy.

“In such cases, the victim explained away the snooping by considering it as a sign that they should reassure their romantic partner about their commitment to the relationship. They ended up excusing the behavior and, in some cases, continued to give the other person access to their phone,” Beschatnikh said.

That leads us to the real question: why do people snoop? Mainly, there was a feeling of jealousy and a desire to “control relationships with others”. Some respondents said they were joking around, while others reported trying to use stolen information for financial benefit or malicious reasons. Generally speaking, people are more likely to have their phones accessed by people within their inner circle, who often look at text-based conversations (text messages, instant messages, and email). When do people snoop? Mostly when the owner of the phone takes a shower or bathroom break. So if you don’t trust those around you, bring your phone into the bathroom, say researchers.

Though it is a small sample size with self-reported data, the researchers say their findings provide insight into why people go through other's personal information from the perspective of those who were directly involved.

“The fact that people snoop is widely known, but we know much less about exactly why they do what they do, and about the eventual impact on their relationships,” said Beschastnikh. “This study contributes new insights to that discussion straight from those who have experienced snooping, and hopefully prompts more research down the line.”

A Pew survey found that 12 percent of US mobile phone owners reported having had another person access the content of their phone in a way that they felt intrusive, while 9 percent of participants in a separate online survey reported having used someone else’s mobile phone without their permission. In yet another survey, almost one-third of participants reported having “looked through” someone else’s phone without permission in the last year alone – a statistic that is higher among younger people and those who keep secretive information on their own phones.