The distribution of effect sizes in the funnel plot (see Figure 1) further indicates a bias toward statistically significant results since there was a slightly higher number of effect sizes to the right of the unweighted average effect size (d = 0.99). The plots would be more equally weighted on both sides of the mean if no bias were present. Note that effect sizes of studies with larger sample sizes clustered largely to the left of the aggregated mean, while those with smaller samples were clustered to the right. This asymmetry in the funnel plot may be caused by other variables such as the moderators, which will be discussed in detail later.