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Metacognition, Marshmallows and the Power of Language


Three pieces of great research which show how, as Johnny Nash nearly said, the more we find out, the less we know…

'Words, words, words. I'm so sick of words...'

Back in the late 70s, I was beginning my early training in educational and developmental psychology and one of the first experiments to make an impression on me was the Marshmallow Test. This simple test has become key to understanding determinants of success in schooling and later life.

The Marshmallow or Cookie Test was devised by American psychologist Walter Mischel in 1968 to test impulse control in 4 year-olds.

In filmed experiments, children were left in a small playroom with a plate of sweet biscuits. The researcher told them they could have one cookie now or two when he returned. Most children understood the benefit of waiting, but few could resist eating what had been left in front of them.

What the children did to avoid temptation is important. Films of these experiments show them covering their eyes, pretending to play hide-and-seek underneath the desk, or singing songs.

Mischel and his team posited that the more patient children were better at the skill of meta-cognition or thinking about thinking. If you have these cognitive skills, then you can study instead of watching television, or save for retirement.

More recently, in a related experiment, Angela Duckworth, from Pennsylvania University, gave 12 year olds a choice between a dollar immediately or two dollars the following week. Comparing perfomance in these tests with participants’ academic scores, she found that the ability to delay gratification was a far better predictor of academic performance than I.Q.

Until recently, the rationale behind this has been on thinking skills. In an amusing and informative blog (see below) on cognitive control and executive brain function, Melody Dye from Stanford University develops the thinking sparked by the Cookie Test and discusses the relative importance of vocabulary as a predictor for impulse delay.

Her colleagues Michael Ramscar and Christine Tran tested 3 – 4 ½ year olds for cognitive function, gratification delay and vocabulary size. What they found is that vocabulary is a much, much better predictor of self-control than cognitive function.

The problem with vocabulary is that it is determined by the social variable of home background. If the cognitive training that might have helped practice gratification delay is not as important as the home environment, what does this have to say to those of us who are interested in children’s language learning, reading and later life success?

If vocabulary development is a reliable predictor of self control which, in turn, predicts academic and later life success, what does this tell us about the role of language learning? Should we stop training our children in turn-taking and concentrate instead on Wordbuilder activities?

The truth is more mundane and more complicated. There were never any silver bullet tricks that would teach your child to succeed. This is a multi-factoral conundrum where benefit is to be obtained from parental modeling, family and school vocabulary development and cognitive skill training.

Cognitive training on its own clearly doesn’t predict for better self-control than vocabulary development. Yet, flash cards don’t work, either. None of these will harm your child, of course, and we know one thing for sure, failure to interact with your children or switch off the TV and computer certainly will.

If ever there was an argument for active engagement by parents with their children – playing and talking to them, sitting and reading with them – this is it.


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