Confidence stems in large part from previous experiences and interactions that influence beliefs about what one can and cannot do. Prior science successes and encouragement are thus likely to increase confidence. Typically, high confidence leads to students working harder and more persistently in science. This, in turn, often means greater achievement. As teachers, the way you interact with your both male and female students can greatly boost their confidence in learning science and increase their performance and engagement. Chapter 5 describes several useful strategies to this end.
Resources to support teachers in fostering confidence can be found here and in the links. Those resources include handouts and activities, further reading, links to recommended websites, and short (~ 3 minute) video clips illustrating the importance of this concept to practicing scientists and showing exemplary high school teachers who practice the strategies recommended in the book.