Based on a large survey of high school and college students, Fox and Lawless found that young men were more likely than young women to say they would consider running for office. But this gap was not evident among the high school students, just the college students. Consider this graph:
Among the high school students, the gap is small, but it grows substantially at age 18 and, if anything, continues to grow until age 25.
What is driving this? Fox and Lawless find that college-age women report having important socializing experiences at a lower rate than college-age men — and even than high school girls. Here is a graph based on their results:
In high school, boys and girls are equally likely to say that a parent has encouraged them to run for office. Among college-age men, the percent who says they have been encouraged by a parent increases, but the percent among women decreases. Meanwhile, college students are more likely than high school students to say that they talk about politics with friends weekly, but the difference is larger for men than women.
Fox and Lawless also asked how qualified people felt they would be to run for office in the future. In high school, there is little difference between boys and girls, once again. But in college, men are more likely to say that they would be qualified, while women are more likely to say that they would not be qualified.
Fox and Lawless point out that, in other respects, young men and women are similar:
It is critical to note, however, that [the gender gap in political ambition] is not because young women have less of a sense of civic duty or different aspirations for the future than do men. In fact, when we asked the respondents about their priorities and life goals, we found few gender differences; young women and men were equally likely to want to get married, have children, earn a lot of money, and achieve career success. Male and female respondents were also equally likely to aspire to improve their communities.
The difference is just that young women are less likely to want to effect change via political office.
Ultimately, men and women come to have political ambition because of similar kinds of experiences. It is just that women have them less frequently, especially once they reach college age. This has quite negative implications for increasing the number of women in elective office.