Bernadette Rostenkowski works at The Cheesecake Factory and is studying to earn her Ph.D. in microbiology. She is sweet and has a voice like a kewpie doll might. Penny introduces Bernadette to the perpetually-horny and on-the-prowl Howard Wolowitz and they somehow hit it off after discovering they both have overbearing mothers. (When Bernadette gets angry, she shouts and sounds just like Howard's gravelly-voiced off-screen mother.) Howard jokes that her parents' names are Adolf and Eva. Bernadette is one of the few members of the group who is able to keep Sheldon Cooper in check, by treating him like the child he sometimes acts like. Raj Koothrappali has a crush on her, which makes them both uncomfortable.