The ‘model’ demonstrates a series of actions, some of which are irrelevant to goal retrieval (removing bolt defence, inserting tool into top hole), and some which are relevant to goal retrieval (removing door defence, inserting tool into lower hole).

<p>These actions are illustrated above: (a) dragging bolt; (b) causally irrelevant tool insertion into top hole; (c) causally relevant tool insertion into front hole.</p

Percentage number of participants in each age group who performed all (bolts plus insertions), part (bolts only), or none of the irrelevant action sequence.

<p>Percentage number of participants in each age group who performed all (bolts plus insertions), part (bolts only), or none of the irrelevant action sequence.</p

Percentage number of participants in each age group who dragged or pushed the bolts as a function of technique witnessed.

<p>Percentage number of participants in each age group who dragged or pushed the bolts as a function of technique witnessed.</p

Illustration of the experimental set-up in the Science Exploration Zone of Living Links.

<p>Experimenter 2 acting in the role of a zoo visitor (A) observes Experimenter 1 (B) manipulating the experimental puzzle box (D). The puzzle box is situated amongst other interactive activities (C) available for the public to explore.</p