How facial aging affects perceived gender: Insights from maximum likelihood conjoint measurement

Conjoint measurement was used to investigate the joint influence of facial gender and
facial age on perceived gender (Experiment 1) and perceived age (Experiment 2). A set
of 25 faces was created, covarying independently five levels of gender (from feminine to
masculine) and five levels of age (from young to old). Two independent groups of
observers were presented with all possible pairs of faces from this set and compared which
member of the pair appeared as more masculine (Experiment 1) or older (Experiment 2).
Three nested models of the contribution of gender and age to judgment (i.e., independent,
additive, and saturated) were fit to the data using maximum likelihood. The results
showed that both gender and age contributed to the perceived gender and age of the
faces according to a saturated observer model. In judgments of gender (Experiment 1),
female faces were perceived as more masculine as they became older. In judgments of age
(Experiment 2), young faces (age 20 and 30) were perceived as older as they became more
masculine. Taken together, the results entail that: (a) observers integrate facial gender
and age information when judging either of the dimensions, and that (b) cues for
femininity and cues for aging are negatively correlated. This correlation exerts stronger
influence on female faces, and can explain the success of cosmetics in concealing signs of
aging and exaggerating sexually dimorphic features.