Theoretical and Empirical Turn Proportions.

Proportion of turns relative to the location of the last-uttered item, for iid sampling (top row), a “small-transitions” iid sampler that discards items more than 1 SD away from the last item (middle row), and the observed values from participants (bottom row). While small Distances alone would lead to lower Turning Points values than iid sampling, the expected turns would be the same at the center of the distribution (i.e. around 50%). We show that people follow their current trajectory over and above what would be expected from small transitions only, going below the 50% threshold at the center of the distribution. Note: To be able to compare different participants in Experiment 1, we standardized their sequences and calculated a Z score of the heights uttered. Then we divided these scores into 13 possible bins, with midpoints at −3, −2.5, …, 0, …, 3, and counted the relative frequency of turns in each bin. We show bins -2 to 2 only to aid visualization. The shaded area represents the region we defined as the center in each condition. Simulated plots were generated from 100 sequences each.