Experimental design

This phase was similar in both conditions. Instructions were similar to those of Osiurak et al. (41) (see https://osf.io/m3d7q/). The participants had five trials to optimize the speed of a wheel that descended a 1-m-long inclined track. They could move four weights to any of 12 discrete positions along each spoke and were free to choose their own configuration (from 1 to 12, with 1 being the closest position to the center of the wheel and 12 being the farthest position from the center of the wheel). After the participants used a marker pen to indicate the positions of the four weights on the wheel (i.e., a paper version of the configuration), the experimenter positioned the weights on the physical wheel accordingly. The participants were not allowed to move the weights on the physical wheel themselves to prevent damage due to potential repeated awkward manipulations. The wheel also needed to be placed correctly in its initial position and the release had to be accomplished without any abrupt movements to avoid a modification of the trajectory of the wheel. Nevertheless, the participants could scrutinize the experimenter moving the weights and releasing the wheel as well as the wheel descending the track. The time it took the wheel to travel down the track was automatically recorded by a computer program (see https://osf.io/m3d7q/). The wheel speed and the associated configuration were then displayed to the participants, who had as much time as they needed to consult their last two configurations and choose the next one. As explained above, we used a paper-and-pencil method to display the wheel speeds and the associated configurations (see https://osf.io/m3d7q/). After three trials, the experimenter reminded the participants in the Speed-Only condition that the wheel speeds of their last two trials would be transmitted to the next participant in the chain. In the Configurations+Speed+Noise condition, the experimenter reminded the participants that their last two configurations and the associated speeds would be transmitted to the next participant in the chain. In this condition, a random noise was introduced by the experimenter into the wheel configurations before transmission, by moving the four weights six positions closer to or farther from the center of the wheel (i.e., the absolute sum of the modifications equaled 6). Thus, if the configuration of the wheel of a participant on their fourth trial was, for instance, Position_{Top Weight}: 9; Position_{Front Weight}: 9; Position_{Bottom Weight}: 5; Position_{Back Weight}: 5, a random modification of six positions was applied (e.g., +1;−3;+2;0), which modified the configuration of the wheel (i.e., Position_{Top Weight}: 9 + 1 = 10; Position_{Front Weight}: 9–3 = 6; Position_{Bottom Weight}: 5 + 2 = 7; Position_{Back Weight}: 5 + 0 = 5). The configurations thus modified and their associated speeds were then transmitted by the experimenter to the next participant. The computer program used to generate these random positions is available at https://osf.io/m3d7q/. The introduction of this random noise frequently generated wheels that did not descend (i.e., speed of 0 m hour⁻¹). Sometimes, the program could generate two configurations with null speed for the same participant. To ensure that the participants in the second-to-fifth generations received at least one configuration with a wheel that descended, we reran the program until we obtained a wheel with a non-null speed for the second configuration when the speed associated with the first configuration was already null. There were 28 chains of five participants each (i.e., 14 chains in the Speed-Only condition and 14 chains in the Configurations+Speed+Noise).

In both conditions, the participants completed this phase after the building phase [see (41)]. They were instructed that they would be presented with items consisting of four wheels and that they would have to choose which of the four wheels would roll down the rails faster in their opinion. They could take as much time as they needed to complete the test. They received no feedback. All the participants saw the same items in the same order. The understanding test consisted of 24 items (i.e., 12 inertia items and 12 center-of-mass items). The test is available at https://osf.io/m3d7q/. Last, the participants had to write a brief theory (i.e., less than 340 characters long) about the functioning of the wheel system, which always started with “The wheel covers the distance faster when…” [for a similar procedure, see (22)]. The data collected about these theories are not discussed in the present report.