The use of cognitive verbs like 'think', 'know', 'remember' and 'believe' by mothers when reading picture books to their children has a beneficial effect on their children's later ability to understand other people's mental states – what psychologists call their 'theory of mind'.
This has been demonstrated before with young children aged between three and four years old. But now Juan Adrian and colleagues have found it also holds true with children up to seven years old, even as maternal influence might be expected to diminish.
The researchers observed the way 41 mothers read picture books to their children who were aged between three and six years. The children's understanding of other people's mental states was also tested, for example by showing them that a Smarties tube contained counters, not Smarties, and then asking them to predict what another child would think was inside the tube.
A year later, the mothers were again observed reading to their children, and again the children's understanding of other people's mental states was tested, this time using some more difficult tasks.
The longitudinal nature of the experiment allowed the researchers to check that mothers' language style really had a causal role. They found that mothers' use of more cognitive verbs at baseline predicted their child's understanding of mental states a year later, even after controlling for children's baseline understanding of mental states and mothers' educational background. But the reverse wasn't true – children's understanding of mental states at baseline didn't predict mothers' later use of cognitive verbs.
A more detailed breakdown of the mothers' reading style showed that it was particularly references to story characters' mental states and explaining their thoughts and actions using 'think' terms (e.g. Mother says: “...this boy sees so many people and thinks, 'I'll pretend I don't know what's going on and I'll push to the front of the queue'”) that was predictive of their children having a more advanced understanding of mental states a year later.
Adrian, J.E., Clemente, A. & Villanueva, L. (2007). Mothers' use of cognitive state verbs in picture-book reading and the development of children's understanding of mind: A longitudinal study. Child Development, 78, 1052-1067.