As explained in Chap. 2 , hereditary tendencies are only expressed through the processes of behavioral development, with genes being in a constant state of mutual causal transaction with the surrounding environment. In this chapter, we address the behavioral development of political engagement, irrespective of ideology. Whether right or left leaning, we ask, what developmental and environmental factors cause some individuals, but not others, to invest time and energy in politics? Actively participating in politics, such as running for local school board elections, or supporting a candidate’s campaign, are time-consuming activities, though so are the more prosaic tasks of reading newspapers, watching programs, registering to vote, and voting. Again, irrespective of party affiliation, why do some invest in these activities more than others? The social scientific literature documents an array of associations between economic distress and political participation; people become more involved in distressed macroeconomic circumstances. Then there is literature on rational ignorance, which explains declining engagement as a function of voter efficacy. In other words, people vote when they think their vote counts, and they otherwise abstain. These are interesting phenomena, but they broadly affect all voters. This chapter consequently focuses on the individual differences that affect some voters over others. Deferring the discussion of details, we herein consider political engagement as an active attempt to shape the conditions to which one is subject.