Two sources of bias explain errors in facial age estimation

Accurate age estimates underpin our everyday social interactions, the provision of age-restricted services and police investigations. Previous work suggests that these judgments are error-prone, but the processes giving rise to these errors are not understood. Here we present the first systematic test of bias in age estimation using a large database of standardized passport images of heterogeneous ages (n = 3948). In three experiments we tested a range of perceiver age groups (n = 84), and found average age estimation error to be approximately 8 years. We show that this error can be attributed to two separable sources of bias. First, and accounting for the vast majority of variance, our results show an assimilative serial dependency whereby estimates are systematically biased towards the age of the preceding face. Second, younger faces are generally perceived to be older than they are, and older faces to be younger. In combination, these biases account for around 95% of variance in age ...

准确的年龄估计是日常社交互动、年龄限制服务供给以及警方侦查工作的重要基础。既往研究表明，这类年龄判断极易出现误差，但导致这些误差产生的认知过程尚未被探明。本文首次基于涵盖多年龄段个体的标准化护照照片大型数据库（样本量n=3948），对年龄估计偏差开展系统性检验。我们通过三项实验，测试了覆盖多个年龄层的判断者群体（总样本量n=84），结果发现平均年龄估计误差约为8岁。研究表明，该误差可归因于两类可分离的偏差来源：其一，该偏差可解释绝大多数的变异量，我们的结果揭示了一种同化性序列依赖效应，即年龄估计会系统性地偏向于前一张呈现面孔的实际年龄；其二，年轻面孔通常会被感知为比实际年龄更年长，而年长面孔则通常会被感知为比实际年龄更年轻。上述两类偏差共同解释了约95%的年龄估计变异……