INVITED REVIEW Age Estimation from Faces and Voices:

In social interaction, age is one of the most important factors (Gladwell, 2006). Indeed, the age of our interlocutor strongly deter-mines the way we interact with her or him. In almost all societies, people speak to younger persons and to older persons dif-ferently. The lexical and syntax of messages is likely to change radically according to the relative age of the interlocutor (e.g., Kemper, Ferrell, Harden, Finter-Urczyk, & Billington, 1998; Ryan, Giles, Bartolucci, & Henwood, 1986). For instance, some studies showed that young people tend to speak more slowly and loudly to older people (e.g., Hummert, Shaner, Garstka, & Henry, 2006). Therefore, in everyday life, it is common to estimate the age of people in order to respond in a befitting or adjusted manner. This process occurs in just a few seconds and simply by looking at the person and listening to th