7 subtle behaviors that reveal someone can’t be trusted—even if they seem friendly

When I was in college, I had a classmate who seemed like the friendliest person in the world. She’d always greet me with a bright smile, ask about my day, and insist that we study together. At first, I was thrilled to have found someone so supportive.

Over time, however, I noticed something strange. She’d cancel plans at the last second, talk behind our mutual friends’ backs, and act suspiciously evasive whenever I asked about her own life. It felt unsettling, but I brushed off the warning signs because I wanted to believe the best in her.

In the end, it turned out she was using me for notes and networking opportunities.

That experience taught me a valuable lesson about paying attention to subtle signals. Sometimes, people who appear warm and charming can carry red flags we don’t immediately see. Here are seven subtle behaviors that I’ve learned to keep an eye on.

1. They overpromise but rarely deliver

Few things are more frustrating than someone who makes grand commitments but always seems to “forget” or back out at the last minute.

They might promise an introduction to a key contact, say they’ll help you solve a complicated project, or even insist they’ll be there to support you during a tough time—yet nothing materializes.

What makes this so tricky is that they’re often persuasive. Their promises aren’t always blatant lies; sometimes they’re just overly optimistic statements that never come to fruition.

In my early days as a wellness coach, I had a colleague who constantly pitched ideas about collaborating on workshops. He’d talk about how we could “change the industry together,” but then vanish when it was time to do the real work.

Repeated overpromising but under-delivering can be a clue that someone’s friendliness is superficial. Trust is built through consistent follow-through, not empty words. Pay attention to the pattern, not the pitch.

2. They gossip but never open up themselves

I’ve always believed in the power of sharing personal stories—both the good and the messy—to foster genuine connections. But whenever I see someone who loves to pry into other people’s lives, yet offers nothing about themselves, I get that uneasy sense that something’s off.

It’s not that everyone has to share their most vulnerable secrets on day one; it’s more about noticing whether the exchange is reciprocal.

If they press for details about your relationship status, finances, or family issues but remain vague about their own experiences, it can indicate they’re collecting information without any intention of genuine sharing.

According to an article I read on Psychology Today, gossip can serve as a social bonding tool, but it also becomes a weapon for those who lack empathy. If you feel that someone’s interest in your life is purely for the sake of having something to talk about behind your back, it’s wise to proceed with caution.

3. Their body language doesn’t match their words

A huge part of communication happens beneath the surface—through facial expressions, posture, and tone of voice.

Even if someone’s words sound kind, watch for inconsistencies in their nonverbal cues. They might give you a compliment like, “Wow, you did an amazing job on that presentation!” yet their eyes dart around or they don’t maintain natural eye contact.

I first picked up on this during my time as a competitive athlete, where reading body language was almost as important as reading the scoreboard. I’d meet people who offered polite congratulations but carried stiff posture and disinterested expressions.

Eventually, I learned to trust my instincts. Genuine people tend to show congruence between what they say and how they carry themselves— their facial expressions, gestures, and tone line up with their message.

So if you feel that your friend’s or colleague’s warmth is forced or that their smile doesn’t quite reach their eyes, pay close attention. Subtle discomfort often reveals bigger truths.

4. They deflect accountability

One of the clearest signals that someone can’t be relied upon is their inability to accept responsibility. They might be quick to blame external circumstances, other people, or “bad timing” for any mistakes or setbacks in their life.

Have you ever heard someone say something like, “I’m sorry you feel that way,” instead of “I’m sorry for what I did”? That’s a classic deflection tactic.

It may seem small, but it adds up. I once had a roommate who would consistently skip her share of the chores. Whenever I brought it up, she’d say, “Well, you never reminded me!” as if I was her personal alarm clock. She was friendly enough to chat with over coffee, but in serious matters, she never admitted fault.

Genuine trust requires mutual respect and owning up to mistakes. If someone’s pattern is to point fingers every time, it’s a sign they might not be there for you when it really counts.

5. They keep score in relationships

Have you ever felt like someone was mentally tallying every favor or kind gesture they did for you? It’s that subtle but uncomfortable feeling that if they lend you five dollars, they’ll expect something in return—maybe not money, but a willingness to do them a favor at a moment’s notice.

As Brené Brown often emphasizes in her work on vulnerability, healthy relationships flourish when people give without calculating the return on investment. When someone constantly keeps a running balance sheet— “I did this, so now you owe me that”— it undermines genuine warmth.

In my own friendships, I’ve noticed that the people I trust most are those who help because they want to, not because they expect me to repay them in a specific way. If you sense that someone is performing nice acts but quietly stacking up “credit” to use against you, they might not have your best interests at heart.

6. They subtly shift blame onto others

This is slightly different from deflection because it involves a more active strategy of painting another person as the problem.

It often goes hand in hand with gossip, but it can be more insidious. They might say things like, “You know, people are saying you’re difficult to work with,” when in reality, it’s their own opinion disguised as group consensus.

A friend of mine faced this at her workplace. She had a colleague who would start sentences with, “Well, the management team believes…” but when she double-checked, management had never said anything of the sort.

If someone regularly frames feedback or criticism with phrases that implicate others— “They all think this about you” or “Everyone’s worried about your behavior”— it’s a red flag that they’re trying to dodge the discomfort of being honest themselves.

This blame game undercuts trust because it hides the real source of negativity behind a veil of alleged group opinion.

7. They show inconsistent warmth or charm

People who want to manipulate often rely on charm. They might shower you with compliments or small gifts, then suddenly turn cold if you don’t give them what they want. This hot-and-cold behavior can leave you feeling confused, as you’re never sure which version of them you’ll encounter.

Dr. Andrew Huberman from the Huberman Lab Podcast suggests that our nervous system picks up on consistent patterns of behavior to determine safety. When someone’s behavior fluctuates between extremely friendly and oddly distant, our internal alarm bells start ringing—even if we can’t pinpoint why.

I remember a colleague who was all smiles on Monday, praising everyone’s ideas, and then by Wednesday, he’d ignore my emails and act annoyed by any question.

These unpredictable shifts in demeanor left me feeling off-balance and wary. Authentic, trustworthy people don’t keep you guessing; they maintain a relatively consistent manner over time.

Conclusion

Whether in friendships, professional collaborations, or romantic relationships, we rely on trust as a foundation for honest and secure connections.

That doesn’t mean everyone has to be perfectly transparent or free from flaws—we’re all human—but paying attention to these subtle signs can protect you from emotional or even professional fallout.

If someone’s words rarely match their actions, or if they deflect personal accountability and gossip without reciprocating genuine vulnerability, consider it a nudge to tread carefully.

I’ve found that maintaining healthy boundaries and staying attuned to my instincts have saved me more than once. At the end of the day, trust is earned through consistent kindness, accountability, and openness.

When the subtle behaviors don’t align with that, it’s worth taking a closer look at how much you’re willing to share or rely on that individual. After all, your energy—and peace of mind—deserve protection.

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