Research quantifies how much speakers` first language affects learning a new language
(PHYSorg.com Medicine & Health)

Language research has documented that people tend to draw inferences about speakers based on how they talk. These often implicit inferences can occur in the blink of an eye and can affect how smart we think someone is, how much we like them, and more. This is also the case for the non-native accents typically present in speakers who learn a new language later in life.