Shared memory:

1. "New information" such as finally snatching an elusive name of a musical thanks to a chain of prompts between the two parties.

2. Richer, more vivid descriptions of events including sensory information.

3. Information from one partner painting things in a new light for the other.

Differences between the couples were crucial. Those who structured their approach together and were more prepared to riff off the other's contributions did better than those who were more passive or critical. Richer events were also better remembered by partners who rated their intimacy as higher.