Therefore, there were no age differences in the tendency to ask
an individual for a favor when they were smiling compared with
when they were displaying a neutral expression, indicating that
older and younger adults were equally responsive to smiles when
paired with neutral faces. However, age-related differences were
found in the critical condition that required participants to discriminate
between enjoyment and nonenjoyment smiles. Younger
adults were most likely to ask another individual for a favor when
that person was displaying an enjoyment smile rather than a
nonenjoyment smile, in line with previous results indicating that
younger adults find those with enjoyment smiles more approachable,
generous, and sociable (Frank et al., 1993; Johnston et al., in
press; Mehu et al., 2007; Miles, 2009). Older adults were also
more likely than chance to choose to ask an individual for a favor
when they were displaying an enjoyment (vs. nonenjoyment)
smile. However, of importance, older adults differentiated between
these smiles to a lesser extent than younger adults. These results
suggest that older adults may be less able to detect the social
meanings behind different types of smile and thus are less likely to
make judgments on the basis of the distinct social affordances that
only enjoyment smiles offer (e.g., increased cooperation, approachability,
generosity, and reciprocation of social contact).