Do you ever have that feeling that nobody’s really listening to you? I hate to be the one to break it to you, but that might be because…you do too much talking.

It’s easy to fall into the habit of over-sharing. Everybody wants to be heard, after all. And talking about yourself can be as pleasurable as chocolate. Or sex.

No kidding. Neuroscientists at Harvard checked it out. Talking about yourself and your opinions stimulates the brain and produces the neurotransmitter dopamine. Just like eating a candy bar or being in bed with your sweetie.

Of course, the better it feels, the more likely we are to keep talking.  And talking. And talking. Chronic blabbermouths get that way because they’re hooked on the pleasure hormone and they’ve discovered, even if unconsciously, how to get more of it.

We know what else happens when we go on and on and on about ourselves—we lose our listener.

Here’s the thing. Listeners lose interest way sooner than I would have guessed. So how do you know when it’s time to say when?

Here’s a handy guide to conversations from San Francisco radio host Marty Nemkow.

• You get a green light as you begin to talk about the embarrassing thing that happened at work today, or what you think of your boneheaded congressional representative, or where you’re going for your long-overdue vacation. Whatever the particulars, the star of the story is you.

And if you’re saying something relevant to the conversation, maybe even related in some way to your conversational partner, they’re liking you.

So the light stays green. For 20 seconds.

• Then the light turns yellow, and you know it’s getting more likely that the other person is beginning to lose interest. They’re starting to think you’re awfully long-winded. You get about another 20 seconds in this caution zone.
• And then, only 40 seconds into whatever you’ve been saying, your light turns red. And yes, red means “STOP.”

Nemkow says there might be a rare time when you’ll want to barrel through that conversational red light and keep talking. But almost always you’re better off to stop or you’re in danger of being tuned out. Or interrupted. Or talked over.

So unless you’re an extremely gifted story-teller with amazing experiences to share, and an audience that hungers to know more… if you talk for much more than half a minute at a time, they’ll be thinking you’re boring and way too chatty.

My own experience? I’m pretty concise, thanks to years of practice telling even the most important stories in 25 seconds, with room at the end to say, “Catherine Johns, WLS News.”

But this idea that the red light comes on 40 seconds in? That made me stop and think. I’m going to pay close attention to upcoming conversations and see how often I stick to the time limit. Or what happens when I don’t.

I invite you to experiment with me. Post a comment below to share your observations.