Hold up a cup and ask what it is. A cup, a container, a weapon, a paperweight, an odd object to a creature with no hands. The answer depends on who is asking.

What the research says

A meta-analysis of randomised trials found that even self guided smartphone apps can teach acceptance, mindfulness and self compassion, with small effects against control conditions. Ways of relating to your own experience behave like teachable skills rather than fixed features of a person. The effects were small, which is the honest size for something learned a few minutes at a time.

Strength of evidence: one line of research. A single study, or a theoretical account.