Researchers at the University of Texas said the style of speech couples adopt after meeting can even predict whether or not they will form a relationship, a major newspaper reported.
Those that quickly fall into the same pattern, subconsciously synchronising their use of certain words, are much more likely to become romantically involved.
The study led by Professor James Pennebaker focused on “function words” such as the, a, be, anything, and, that, will and him.
Professor Pennebaker and his team examined whether the speaking and writing styles couples adopt can predict whether they are attracted to each other and the long-term strength of any relationship.
They conducted two experiments in which a computer program compared partners’ language styles.
In the first study, pairs of college students had four-minute speed dates while their conversations were recorded.
Almost every pair covered the same topics such as what they were studying, where they were from and whether they liked college.
Although every conversation sounded more or less the same to a casual listener, text analysis revealed stark differences in language synchronisation.
The pairs whose language style matched more than the average were almost four times as likely to want to meet again compared with pairs whose speaking styles were out of sync.
A second study revealed the same pattern in online chats between dating couples over the course of 10 days.
Almost 80 per cent of the couples whose writing style matched were still dating three months later, compared with just half of the couples who didn’t match so well.
The finding has been published in the journal Psychological Science.