This study uses variationist quantitative methods to explore adjective intensification in Middle English. Using the Penn-Helsinki corpus and the Paston letters, the study shows how linguistic, social, and stylistic factors influenced historical intensification. A strong gender effect is observed, with women amplifying more frequently than men but men using downtoners more frequently than women. Analysis of changes in the system of boosters shows evidence of women leading in linguistic change, spearheading the use of right as a booster in Late Middle English. Rank of the addressee and relationship to the addressee are also significant factors, with higher rates of amplification in higher-ranked directed communication and communication among family members. Overall, this study highlights how speakers can use intensification to construct socio-stylistic meaning and to mediate power/social relations between the speaker and the audience, illustrating that intensifiers not only convey speaker-related attitudes but also signal interpersonal information such as addressee-orientation. This title is also available as open access on Cambridge Core.