People whose parents divorced score meaningfully lower on measures of romantic trust than people whose parents stayed married, according to a 2023 study published in Frontiers in Psychology that surveyed university students on dyadic trust, attachment style and relationship history. The same study found that people who had lived through a breakup scored lower on trust than those in ongoing relationships. Past relationships leave a measurable imprint on how much a person trusts the next one — which is exactly why bringing up an ex with a new partner feels so loaded. Say too little and it can read as secrecy. Say too much and it can read as still being tethered to the past. There is no universal script, but relationship research does offer real guardrails for where that line tends to sit.
Why the Question Feels Like a Trap in the First Place
The Frontiers in Psychology research found that both anxious and avoidant attachment styles correlate negatively with dyadic trust, and that anxious attachment in particular tends to work indirectly — it first affects a person’s beliefs about independence and equity in relationships, and those beliefs are what then shape trust. In plain terms: a partner’s discomfort with hearing about an ex is rarely really about the ex. It is usually about what that person already believes, based on their own history, about whether relationships are safe and reliable at all. That is worth knowing before a conversation about exes turns into an argument about something else entirely, because the emotional reaction on the other side of the table often predates the current relationship by years.
The Concept Relationship Researchers Actually Use: Gradual Disclosure
Communication researchers have studied how self-disclosure builds intimacy since the 1970s, when psychologists Irwin Altman and Dalmas Taylor introduced social penetration theory — the idea that healthy relationships deepen through a gradual, reciprocal exchange of personal information, moving from surface-level facts to more vulnerable ones as trust is established, not all at once. Applied to talking about exes, that framework suggests the right amount to share is rarely “everything” in one sitting or “nothing” indefinitely. It is a little more with each stage of trust: the fact that a serious relationship existed, early on; the general reasons it ended, once the relationship has some footing; and only with real trust, the more vulnerable details — what hurt, what was learned, what changed as a result.
What Actually Undermines Trust Isn’t the Ex — It’s the Secrecy
The Gottman Institute, whose research has tracked what predicts relationship breakdown for decades, frames betrayal in a way that reframes this whole question: “betrayals are founded on two building blocks: deception,” among others — the withholding of a partner’s real needs or history in order to avoid conflict. Their research on hidden relationships and interactions offers a useful test: something becomes a betrayal specifically “if your partner would be upset by the things you’ve shared or would be uncomfortable watching the interaction.” Applied to exes, that reframes the anxiety most people have backwards. It is rarely the existence of a past relationship that damages trust in a new one. It is discovering, later, that a partner actively concealed something relevant — a communication pattern, an unresolved connection, a reason a relationship ended that turns out to matter to the current one too.
The Amount That Tends to Work
Synthesizing the research: the goal is not maximum disclosure or minimum disclosure, it is disclosure that scales with the stage of the relationship and stays honest rather than curated. Early on, acknowledging that meaningful past relationships exist, without a full accounting, respects both the new partner’s need for basic context and the fact that trust has not yet been earned in either direction. As the relationship matures, filling in more — especially anything that shaped how a person shows up in relationships now — tends to build the kind of trust the Frontiers in Psychology data shows gets damaged by divorce and breakups in the first place. What erodes trust is not the ex being part of the story. It is a partner sensing there is a version of the story being kept from them — and that sense, once it takes hold, is far harder to undo than any conversation about a past relationship would have been in the first place.
