He describes an occasion where he tested out the universality of the eyebrow - lift gesture .
Attenborough muses on the purpose of human eyebrows , suggesting that they were originally used by our ancestors to communicate through expressive facial gestures , much as many primates do today .
Attenborough describes an occasion where Attenborough tested out the universality of the eyebrow - lift gesture .
Attenborough muses on the purpose of human eyebrows , suggesting that they were originally used by our ancestors to communicate through expressive facial gestures , much as many primates do today .