In accordance with Lakovian cognitive linguistics in metaphoric analysis, this paper aims to explore the human cognitive capacity of metaphoric conceptualization of body parts. A contrastive analysis on the cognitive features of metaphorical expressions utilizing various body parts pertaining to the ‘head’ domain, e.g., face and tongue in the English and Farsi languages is carried out. After a cross-linguistic comparison of metaphors in both languages, five main linguistic categories emerge. Similarities and differences of metaphor construction, mappings and mechanisms in both languages used to convey common concepts are highlighted using these categories. While corroborating Lakoff’s approach whereby metaphors constitute an inherent part of language itself, it is shown that there is a universal cognitive grid from which different languages externalize the world differently through semiosis. Therefore, the main aim is to show how language invariance and variation may be explained within a cognitive framework. These universals are due to cognitive constraints, whereas languages owe their variation to the options they have out of the cognitively available pool. They are limited to their selections which are restrained by cultural and perhaps religious factors of semiotic mechanisms which are cognitively accessible to them.