Emotion labelling varies with lexical complexity more than age in face pareidolia images.

Forced choice paradigms constrain the emotion labels available to participants, limiting the range of lexical responses elicited by emotional stimuli. To characterise emotion labelling when this constraint is removed, two studies examined how adults freely describe emotion in inanimate objects with face-like features, stimuli for which no single emotional interpretation is correct. In Study 1, adults aged 20-77 labelled emotion in face pareidolia images, allowing assessment of both response diversity and lexical complexity. Lexical complexity was more strongly associated with label diversity than age or cognitive functioning. In Study 2, younger and older adults evaluated human faces prior to labelling face pareidolia images. Exposure to basic emotion labels reduced the number of unique labels subsequently generated, indicating that earlier category activation constrained later labelling. Across studies, when not constrained by predefined labels, individual differences in lexical complexity, more so than observer age, were associated with more diverse emotion descriptions. These findings highlight the value of free-labelling paradigms. They also suggest that variability in emotion labelling with age depends on task constraints, and further demonstrate that individual differences in one's emotion lexicon matter to how emotion is described.