Almost nobody is good at telling the difference between someone being friendly and someone being interested. The research on this is unusually clear, and it says something specific about which direction you are probably getting it wrong.
It is one of the most common questions I get, in one form or another. Was that flirting, or were they just being nice? People ask it about a coworker, a classmate, someone at the gym, a person they have been talking to for weeks. And underneath the question is usually a quiet worry about looking like a fool.
So let me give you what the research actually says, because it is more useful than the usual list of signs.
Everybody is bad at this, and not in the same way
In 1988, two psychologists named Shotland and Craig ran a study asking whether people are able to tell the difference between friendly behavior and sexually interested behavior. The good news is that people can tell the difference. That part works.
What they found is that the threshold sits in a different place depending on who is doing the reading. Men consistently perceive more interest in a situation than is actually there. Women consistently perceive less.
A more recent study put numbers on how hard this is in practice. Researchers paired college men and women for ten-minute conversations and afterward asked each person whether they had flirted, and whether they thought their partner had. Both groups were good at spotting when someone was not flirting, over eighty percent accurate. But at recognizing when someone was flirting, men got it right about a third of the time and women about a fifth.
Your gut is miscalibrated, and it is miscalibrated in a direction you can predict. That is genuinely useful, because a predictable error can be corrected.
What that means for you
If you are a man, you are inclined to read interest into ordinary friendliness. She is being warm because she is a warm person, and you are reading a green light. That is worth knowing before you act on a feeling.
If you are a woman, you have the opposite problem. You are inclined to file genuine interest under he was just being nice. When you catch yourself concluding that, understand that you are more likely to be wrong about it than right.
In both cases the correction is the same. Stop trusting your overall sense of how it is going, and start reading specific behavior instead.
Read the cluster, not the cue
Any single signal on its own is noise. Somebody laughing at your joke means nothing. Somebody touching your arm once means nothing. People are inconsistent, and plenty of them are warm to everyone.
What means something is several signals pointing the same direction at the same time. Here is what to actually watch.
Eye contact, and especially the second look. One glance could be anything. Eyes that look away and then deliberately come back chose to. That return trip is one of the most reliable signals there is.
Where their body is pointed. Are they facing you squarely? Feet count double here, because people aim their feet at whatever is actually holding their interest and almost nobody thinks to manage their feet. Knees, if they are sitting.
The length of their answers. This might be the most useful cue on the list. An interested person gives you long, detailed answers, because they are feeding a conversation they want to keep having. Short answers, over and over, with a still body, means the opposite.
Mirroring. When you shift your weight and they shift theirs, when you pick up your drink and theirs follows a moment later, their attention is locked onto you at a level they are not aware of. Nobody does this on purpose, which is exactly why it is worth reading.
Whether they are building or closing. Are they asking you things? Bringing up something you mentioned earlier? Finding reasons for the conversation to continue? People do that when they want more of it.
When the cluster is clear, believe it
Four of those pointing the same way is not noise. It is an answer, and it is worth trusting even if some voice in your head is arguing with it.
And when the cues point the other way, believe that just as quickly. Short answers, a body angled toward the exit, eyes touring the room. That is also an answer, and taking it gracefully the first time is one of the more attractive things a person can do.
None of this makes you a mind reader. What it does is replace a feeling you now know to be unreliable with observations that are not. That is usually the difference between people that read others well and people that do not, and it is entirely trainable.
Make the reaching-out easier
Knowing how to start a real conversation takes most of the dread out of putting yourself out there. My free guide gives you three questions that do exactly that.