Investigating the stability of individual differences in face recognition behavior.

Individual differences in face recognition abilities are characterized as heritable and resilient to change. However, this work is largely based on inter-individual differences, tends to include participants with extreme behavior (e.g., prosopagnosia, super-recognizers), and does not accommodate patterns of bias in intra-individual recognition behavior. Here, we investigated the continuity and stability of intra-individual differences in face recognition behavior among emerging adults using two tasks of unfamiliar face recognition that differ in the gender of the faces to be recognized. Although the estimate of stability is high (0.71) across the sample, there are instabilities in the behavior of many individual participants. For example, approximately 16.7% of the sample exhibited a discrepancy between tasks that was larger than 1 SD. Also, stability was more characteristic of extreme behavior. This is a bit surprising given the potential for close generalization of performance across these two tasks (identical structure and similar stimuli). Inter-individual differences in participant characteristics (i.e., gender, age, social skills) do not explain this variability. These findings are difficult to accommodate into current models of individual differences in face recognition behavior.