Here’s a brief experiment for you. If you happen to be working on a play, find a scene partner and run a short dialogue while you have a third person observe. You can also test this with a monologue – just speak a speech to someone else while someone watches.

Now have a normal conversation together, where you ask each other about your ideas on a particular subject. For example, ‘Why do you like living in London?’ Or, ‘What do you think about New York?’

Then ask the person observing what they noticed about your eye contact.

My research suggests that when you are speaking scripted lines you tend to have almost unbroken eye contact. But when you are having a natural conversation, you look away from time to time while you are formulating your thoughts. That’s a natural human trait.

It’s the balance of eye contact and breaking eye contact while speaking that helps create rapport. The listener on the other hand usually makes longer eye contact when listening, except sometimes when they are formulating a response or a new question: that’s when they look away.

This explains why actors often look unnatural when they are trying their hardest to be intense or interesting. Unbroken eye contact, sustained by both of you for too long, goes against normal human behaviour and therefore can look artificial.

So, what is too long? If one character is threatening or trying strongly to influence another character, then unbroken eye contact will help do the trick. But only for as long as that line of thinking lasts. Otherwise it loses effectiveness.

Test this idea for yourself. In everyday life, watch other people having a conversation. Also, notice the pattern of holding and breaking eye contact in your own conversations. Then test it in your next rehearsal.