Estimates of overall intercept (mean response score) in the individual discrimination (ID) and kin discrimination (KD) tasks.

Estimates are from final GLMMs in which all significant effects have been controlled and all nonsignificant factors dropped. Kin discrimination models were therefore run separately for expert versus inexperienced participants. *For the inexperienced subjects, the significant factor ‘trial position’ was also included in the final model (estimate  = 0.23, SE  = 0.074, pMCMC <0.002); trial position values were standardized beforehand (to mean  = 0 and SD  = 1) and hence do not affect the estimate of overall intercept. Significantly positive estimates for the intercept indicate performance at greater than chance levels, and are highlighted in boldface.