What the data actually shows
Work by Justin Mogilski and Lisa Welling on reasons for staying friends with exes found that the motives fall into recognisable groups — including genuine friendship and reliability, practical considerations like shared finances or children, sentimentality, and lingering romantic or sexual desire. Crucially, these different reasons were associated with different outcomes rather than all being equal.
The broad pattern in this and related research is that friendship-based and practical motives tend to be associated with more positive, lower-conflict outcomes, while motives rooted in unresolved romantic or sexual hope are associated with more negative ones, including jealousy and difficulty moving on. The reason behind the contact appears to matter more than the mere fact of staying in touch.
How the relationship ended and each person's attachment style also appear to play a role. Research on post-breakup adjustment suggests that breakups that were mutual or amicable, and people who are more securely attached, tend to navigate post-relationship friendship more smoothly, while a contested ending or anxious attachment can make continued contact harder and slower to settle.
Why this feels different from how it actually is
It can feel like there should be a single right answer — that staying friends is either the mature thing to do or a clear mistake — when the research suggests the same arrangement can be healthy for one pair and harmful for another. The deciding factor is less the label 'friends with an ex' and more the underlying motives and feelings, which are easy to misread, including in oneself.
It also feels different because people are not always honest with themselves about why they are staying in touch. A friendship maintained partly in the hope of rekindling things can look, from the outside and even from the inside, like a purely platonic one. That gap between the stated reason and the real one is part of why outcomes vary so widely.
And the social scripts pull in opposite directions. One says cutting contact completely is the only clean way to heal; another says a 'good breakup' means staying close. Neither is universally right in the data, which points instead to a case-by-case picture shaped by the reasons, the feelings, and how the relationship ended.
The reason behind the contact appears to matter more than the mere fact of staying in touch.
What the research says to do about it
Where the research offers practical guidance, it points toward being honest about the motive. Friendships grounded in genuine liking, or in practical necessities like co-parenting or shared finances, tend to fare better, so naming your actual reason — to yourself first — is a reasonable starting point for judging whether a friendship is likely to help or hinder.
The evidence also suggests that having genuinely moved on emotionally, on both sides, is associated with better outcomes. Where strong feelings remain unresolved, the literature on post-breakup adjustment broadly supports giving those feelings time and space to settle before attempting a close friendship, since contact too soon can slow that process.
For relationships with ongoing practical ties — especially shared children — a workable, lower-intimacy form of contact focused on those responsibilities is a common and reasonable arrangement, distinct from the closer friendships the research finds more contingent on having moved on. The right form of contact depends on what it is actually for.
What the research says does not help
Staying friends as a way to avoid the discomfort of a real ending tends not to help. When the friendship mainly serves to keep a foot in the door or to dodge grief, the research suggests it is more likely to stall moving forward than to support it, even when it is framed as maturity.
Assuming there is one correct rule — that everyone should cut contact, or that everyone should stay friends — does not fit the evidence. Outcomes vary with motives, feelings, and how things ended, so a blanket policy in either direction can be the wrong call for a given situation.
Maintaining a close friendship while one person quietly hopes to rekindle the relationship is the pattern most consistently linked with poorer outcomes, including jealousy and prolonged difficulty letting go. Pretending the feelings are not there rarely makes the friendship the healthy kind.
The honest answer is neither 'always fine' nor 'never works' — it depends largely on the why.
What this looks like in real life
Same arrangement, different why
The label 'friends with an ex' can describe a friendship grounded in genuine liking, or one maintained partly in the hope of rekindling things — and from the outside, and even the inside, the two can look identical. That gap between the stated reason and the real one is part of why outcomes vary so widely.
Practical ties versus close friendship
For co-parents or people with shared finances, a workable, lower-intimacy relationship focused on those responsibilities is a common and reasonable arrangement — and distinct from the closer friendships the research finds more contingent on both people having moved on emotionally. The right form of contact depends on what it is actually for.
Real numbers in context
This is a question where motives matter more than headline percentages, and much of the relevant research is based on surveys and self-report rather than large national datasets — so it is best read as describing patterns and tendencies, not fixed odds. The recurring finding is that friendship- and practicality-based reasons are associated with better outcomes than reasons rooted in unresolved romantic or sexual hope.
Because attachment style and the nature of the breakup also shape how continued contact goes, two people in seemingly similar situations can have very different experiences. Treat the research as a map of what tends to help or hinder, rather than as a prediction of how any individual friendship with an ex will turn out.