Have you ever noticed that when you are trying to find the right formulation or have a word at the tip of your tongue during a conversation, you often look away from the other person, as if it were to help you concentrate? Based on this observation, two researchers from the Cognitive Psychology Department at the University of Kyoto conducted a study to try to explain why we need to break eye contact in order to focus on what we’re trying to say. According to them, there’s a good scientific reason for this.

As noted by the authors, Shogo Kajimura and Michio Nomura: “Although eye contact and verbal processing appear independent, people frequently avert their eyes from interlocutors during conversation.” This observation is all the more noticeable when we’re trying to find words we're not familiar with. The proposed hypothesis is that there is an interference between these processes.

For the study, published in Cognition, they asked 26 volunteers to play a word matching game while watching a computer screen with male and female faces that were either looking directly at them or averting their eyes. While looking at each of the faces, the participants heard a noun that they had to match with a specific verb as quickly as possible. Some words were easier than others. You can try the experiment for yourself: try to find a verb for “scissors" and another for “list.” In the second example, the brain mechanism takes longer because with a pair of scissors you will most likely "cut” something, but you can "make,” "complete," “consult,” or “refer to” a list. In the experimental protocol, the researchers alternated between words that were easy to match and words that had multiple possible matches. Put yourself in the place of the participant who has to look at the face on the screen and make a sentence using the noun provided and the verb he’s found.

So what were the experimental findings? The subjects needed more time to think of the appropriate word when the faces were looking at them directly. However the effect was only significant for the most difficult associations. According to Kajimura and Nomura, this shows that eye contact doesn’t interfere with the brain’s ability to choose words, but the mental effort it requires to maintain eye contact overloads cognitive function to the point where finding the word becomes difficult. In summary, when you’re speaking with someone and trying to come up with the right word, two tasks are competing for cognitive resources: maintaining eye contact and actively thinking about what you want to say.

Though the sample size is fairly small, the research findings are of interest, and the authors want to further explore the links between verbal and non-verbal communication. From now on when someone averts their eyes during a conversation, remember they may not be bored, but simply experiencing cognitive overload!