Average accuracy as a function of whether a reminder was used. “No Reminder”: forced internal condition; “Reminder”: forced external condition. Each pair of dots linked by a line indicates one participant. The red data points are excluded participants. The box plots indicate the median surrounded by the interquartile range (25th and 75th percentile). The whiskers show the minimum and maximum. The preregistered exclusion criteria for the for the accuracies with or without reminder are indicated as horizontal dotted lines (10% and 70% respectively).

People’s tendency to set reminders above or below the optimal offloading strategy (reminder bias) plotted against people’s tendency towards over- or underconfidence (metacognitive bias). The solid line indicates the fitted relationship between both variables. The dashed line represents the 95% confidence interval around it. Each circle represents a single participant.

Standardised regression weights for the ‘anxious-depression’ factor (AD) and the ‘compulsive behaviour and intrusive thought’ factor (CIT) predicting metacognitive bias. Error bars indicate 95% confidence intervals. Asterisks indicate significance: “***”: < 0.001; “**”: < 0.01; “*”: < 0.05.

Standardised regression weights for the ‘anxious-depression’ factor (AD) and the ‘compulsive behaviour and intrusive thought’ factor (CIT) predicting reminder bias. Error bars indicate 95% confidence intervals. Asterisks indicate significance: “***”: < 0.001; “**”: < 0.01; “*”: < 0.05.

Diagram of the mediation analysis testing for the influence of the ‘compulsive behaviour and intrusive thought’ factor (CIT) on reminder bias, both directly and indirectly through the metacognitive bias. Standardised regression coefficients are given for each pat. The value in parentheses indicates the influence of CIT on reminder bias controlling for the influence of the metacognitive bias. Asterisks indicate significance: “***”: < 0.001; “**”: < 0.01; “*”: < 0.05.

A) Example sequence of events within a single trial. Trajectories of movement made by a fictive participant are shown as black arrows. The blue coloured circle corresponds to the left boundary of the square and indicates that this circle must be moved to this side rather than the bottom. B) Example of an offloading decision which participants were required to make before each trial. C) After each decision, they were informed whether or not they would perform the upcoming trial with reminders. D) Confidence was rated once before the introduction of the offloading strategy on a scale ranging from 0 to 100%. E) Sequence of events within the task. All aspects of the task were performed online in the web browser.

Predicting metacognitive bias. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting confidence. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting metacognitive bias with ICAR5 scores as an additional covariate. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting reminder bias. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting absolute number of reminders. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting AIP. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting reminder bias with 2-back d’ as an additional covariate. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting reminder bias with ICAR5 scores as an additional covariate. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other.

Predicting reminder bias with metacognitive bias as an additional covariate (i.e., testing for a moderation effect). All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other; MetaBias = metacognitive bias.

Predicting reminder bias with metacognitive bias and 2-back d’ as additional covariates. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other; MetaBias = metacognitive bias.

Predicting reminder bias with metacognitive bias and ICAR5 scores as additional covariates. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other; MetaBias = metacognitive bias.

Predicting reminder bias with metacognitive bias and ICAR5 scores as additional covariates. All continuous variables are z-transformed. SE = standard error; m = male; f = female; o = other; MetaBias = metacognitive bias.