Colouring in is something we all have done at one point in our lives – mostly in our childhood.
But a new craze is taking hold around the world, and this time it's for adults.
Last week, nine out of 10 international non-fiction books sold in New Zealand were adult colouring books.
They have soared in popularity over recent weeks and often feature intricate and symmetrical designs. This is supposedly good for centring yourself and relaxing by focusing on one small thing at a time.
Psychologist Lisa Markwick joined Paul Henry this morning to explain why an activity previously seen as childish, could be the next big thing.
Watch the video for the full interview with Lisa Markwick