Correcting for the impact of gregariousness in social network analyses

► Differences in gregariousness can strongly affect association indices. ► We propose a new index, the HWIG, which corrects for such gregariousness differences. ► We compared the HWIG with the existing half-weight index (HWI) with simulations. ► Unlike the HWI, the HWI was strongly influenced by the gregariousness of individuals. ► We recommend using the HWIG as an unbiased measure of affinity between individuals.