"He never replies to texts in under three hours: red flag." "She remembers my sister's name: green flag." On social media, lists of red flags, the warning signs supposedly announcing a difficult relationship, number in the thousands. The expression is useful, but it often mixes personal tastes with real danger signs. What does research say about what really damages a relationship, and about what keeps it going?
Where the expression comes from
The red flag has long been a warning signal: on beaches to ban swimming, on racetracks to stop the race, on railways to signal danger. "Red flag" moved into everyday language to mean a sign of trouble, then, with social media, came to focus on romantic relationships and friendships. Its opposite, the green flag, describes reassuring behavior.
The warning signs that really matter
Not all "red flags" are equal. Not liking dogs or hating musicals is a question of compatibility, not danger. Some behaviors, however, are recognized by psychologists and victim support organizations as serious warning signs, especially when they repeat:
- contempt: mockery, sarcasm, humiliation, including "just as a joke". Psychologist John Gottman, who observed hundreds of couples, sees it as the strongest predictor of a breakup of all the behaviors he studied;
- controlling jealousy: checking the other person's phone, demanding to know where they are at all times, criticizing their clothes or friendships;
- isolation: gradually discouraging the other person from seeing friends or family, until you become their only connection;
- an overly intense start: passionate declarations, gifts and plans for the future in the first few weeks, then sudden coldness. This is known as love bombing;
- refusing responsibility: never admitting fault, turning every criticism around, making the other person doubt their own memory;
- ignoring boundaries: pushing after a "no", whether about going out, a photo or an intimate gesture.
These behaviors have something in common: they are not about taste, but about power. In 2007, American sociologist Evan Stark described coercive control: a pattern of monitoring, isolation and intimidation that, taken together, strips a person of their freedom, sometimes without any physical violence. England and Wales made it a criminal offense in 2015.
Green flags: less viral, more important
The behaviors that keep a relationship going are less spectacular, but they are well documented.
Responding to small bids. John Gottman observed newlyweds for a day in an apartment set up as a laboratory. He focused on the tiny "bids" for attention each partner makes: a comment on an article, a sigh, a joke. According to his observations, couples still together six years later responded to these bids about 86% of the time, compared with 33% for those who had split up.
Knowing how to repair. All couples argue. Those who last know how to defuse: an apology, a touch of humor, a hand held out in the middle of a conflict, and a partner who accepts the gesture.
Accepting the other's influence. Listening to an opinion, changing your mind, making compromises: Gottman's work links this ability to more stable relationships.
Being attentive to what the other is going through. Psychologists call it responsiveness: the feeling that the other person understands us, values us and cares for us. It is one of the most consistent ingredients of happy relationships.
Respecting each other's boundaries and life. Encouraging the other person to see their friends, to have their own projects, to say no without fearing retaliation.
Not everything is a flag
The red flag trend has its downsides. A list that is too long can make the smallest flaw look like danger, or be used to judge others without ever looking at yourself. Nobody is an absolute green flag: everyone has bad days, clumsy moments and reactions they are not proud of.
What matters is repetition and response. An isolated behavior that is acknowledged and corrected has nothing in common with a pattern that settles in and that the other person refuses to see. That is also why the most useful question is not "what are their red flags?" but "how do I react?". That is the angle of our quiz Are you a red flag or a green flag?: it puts you in front of your own reactions, with humor.
If a relationship frightens you
If you recognize yourself in several of these warning signs, as a victim or as a witness, you do not have to stay alone with your doubts. In the United States, the National Domestic Violence Hotline (1-800-799-7233) is free, confidential and open around the clock. In the UK, the National Domestic Abuse Helpline (0808 2000 247) offers the same support. In an emergency, call your local emergency number.
In short
- "Red flag" means a warning sign; many of those circulating online are about taste, not danger.
- The real warning signs are about power: contempt, controlling jealousy, isolation, ignoring boundaries.
- Green flags are quieter: responding to small bids, knowing how to repair, accepting the other's influence, respecting their freedom.
- An isolated flaw is not a red flag: what matters is repetition and the ability to question yourself.
To go further, our article on what science says about love compatibility describes John Gottman's "four horsemen".