Having a profound conversation can boost happiness levels, but trivial chatter can be depressing, scientists say.

Psychologists investigated whether happy and unhappy people differed because of the types of conversations they engaged in.

Volunteers wore an unobtrusive recording device to monitor conversations with friends and colleagues for four days.

Researchers then listened to the recordings and identified them as trivial small talk or substantive discussions.

In addition, the volunteers completed personality and wellbeing assessments.

Reporting the findings in the journal Psychological Science, the researchers said the recordings revealed some startling findings.

Greater wellbeing was related to spending less time alone and more time talking to others. The happiest participants spent 25 per cent less time alone and 70 per cent more time talking than the unhappiest.

But the researchers were surprised to discover that the type of conversations people took part in also affected their happiness levels.

The happiest participants had twice as many deep and meaningful conversations and one third as much small talk as the unhappiest.

Matthias Mehl, an assistant professor of psychology at the University of Arizona, said: "These findings suggest that the happy life is social and conversationally deep rather than solitary and superficial."

The researchers conclude that profound conversations may have the potential to make people happier.

They said: "Just as self-disclosure can instill a sense of intimacy in a relationship, deep conversations may instill a sense of meaning in interaction with partners."