[2][3] Schlozman majored in sociology and minored in English at Wellesley College, graduating with a BA in 1968.
[4] She then completed an MA and a PhD in political science at the University of Chicago in 1973 under the supervision of Sidney Verba.
In 1995 Schlozman wrote perhaps her most important work, Voice and Equality: Civic voluntarism and American politics, with Sidney Verba and Henry E. Brady.
This book develops a three-factor model of political engagement that the authors call "civic voluntarism".
[9] John Aldrich reviewed Voice and Equality positively, writing that while it is not a complete theory of political participation in itself, it "will be a component of all kinds of theories of political behavior", while Jane Mansbridge described it as a fundamental advance in the theory of political participation that "documents how even in the realm of citizen participation liberal democracies fail to live up to the norm of equal responsiveness to the interests of each citizen".
[9] Schlozman, Verba, and Brady further developed and tested their resource theory for several decades, and in 2012 they analyzed the implications of wealth inequality on political participation under the resource model in a book called The unheavenly chorus: Unequal political voice and the broken promise of American democracy.
Her 2001 book The Private Roots of Public Action: Gender, Equality and Political Participation, coauthored with Nancy Burns and Sidney Verba, adds another dimension to the three requirements for participation that Verba, Schlozman, and Brady had studied in Voice and Equality: they now consider the influences on participation of citizens' private lives through mechanisms like domestic power relations and differential treatment in the workplace.
[13] The book tests the hypothesis that individuals' private (and necessarily gendered) experiences affect their level of public political participation, using the theory of civic voluntarism.