Want to have a better chat? Scientists say the secret is ‘pink noise’

As an early stab at rules for conversation, Cicero did a fine job: watch your tone, never look bored, never lose your temper and never ramble on, particularly about yourself, he advised.

Now scientists have followed in the great orator’s footsteps and discovered a telltale signature of an enjoyable chinwag. The secret of a mutually satisfying exchange is a healthy dose of pink noise, they say.

The colour of noise tends to animate physicists more than linguists, but researchers at Dartmouth College in New Hampshire in the US found the concept provided fresh insights into what makes a good conversation.

Kathryn O’Nell, the first author on the study, said: “In physics, people talk about pink noise as existing on the edge of chaos, where you can stay at a stable point, but you’re not stuck there for ever.

“It’s particularly cool for conversation, because you can stay somewhere long enough to really get to know each other, to understand the topic, but you’re not stuck there while it gets stale.”

The researchers analysed more than 1,000 conversations between strangers, who answered questions on the chats afterwards. People enjoyed conversations more, wanted to continue chatting, and felt a stronger sense of connection when the tête-à-têtes exhibited more pink noise, they found.

To see whether the effect applied beyond strangers, the researchers ran a similar analysis on conversations between friends about their formative experiences. Again, more pink noise meant more enjoyment.

The effect had real-world consequences, too. When the scientists turned to speed-dating conversations, they found that more pink noise predicted which pairs met up for a second date. Details have been published in Science Advances.

Nailing down what makes a great chat is notoriously tricky, the researchers said. In a bold opening statement to their paper, the authors write: “Good conversation is like pornography – it is difficult to define, but we know it when we see it.”

Colloquially, people talk about being in sync, but the metaphor misses something, said Dr Emily Finn, a neuroscientist and senior author on the paper. “In sync can be incredibly dull,” she said. People can be in sync when they repeat each other’s words and circle a single subject. They might well be immensely bored.

In the study, the scientists took conversations and fed each side into an AI called MPNet. The program scored every turn of the chat on 768 different criteria, covering aspects such as meaning, tone and context. This allowed the scientists to quantify how conversations ebbed and flowed over time.

Conversations exhibit white noise when people fail to follow what has just been said: the chat might jump all over the place, or be dominated by a person who seems oblivious to the other person’s responses. Other conversations can have red noise, which arises when people mirror each other’s language and fall into a conversational rut.

Pink noise lies somewhere in between: a conversational Goldilocks zone that balances stability and flexibility. People will synchronise as they explore a topic, then drift apart as they pull in fresh ideas before converging again to explore those.

The pinkiness of a conversation depends on the people involved, but O’Nell said she suspected the skill could be learned and developed. As part of the study, the team analysed podcasts fronted by two hosts and found that the pinkiness of their conversations increased over the first 50 episodes.

Prof Elizabeth Stokoe, a conversation analyst at the London School of Economics, praised the researchers for moving beyond the idea that “more similarity is better”. But asking whether a conversation is enjoyable risks missing the point, she added.

“There’s a lovely study of a phone call in which a father and his daughter, a young woman with learning disabilities living in residential care, take a long time to say goodbye, and the ending is painful and poignant,” she said. “Reducing conversations to whether they are ‘enjoyable’ can feel bloodless, since many of the conversations that matter most in our lives are like this.”