In this dissertation, research and theorizing from several areas within psychology are brought together to establish a causal chain from perceptions of threat to political attitudes. Threat can lead to anxiety, fear, or both. Threat leads to fear when people can clearly identify the source of the threat; otherwise it leads to anxiety. Because people are highly motivated to alleviate the sense of threat, they will tend to focus on doing so, which results in a reduction of other cognitive activity. If the threat cannot be dealt with directly, people should seek to escape or avoid it. When a threat cannot be identified or dealt with, people experience a lack of control and a high degree of uncertainty, which they are motivated to reduce. People may try to compensate for a lack of control and certainty in one domain by bolstering it in another. Therefore, it is hypothesized that when threatened, people will latch onto social and political attitudes that provide the most easily construed means of restoring control and certainty. It is argued that conservatism is usually better suited for this than liberalism. This is due to some of the main characteristics of conservative ideology, primarily resistance to change and conformity to authority and conventional morality. The five studies reported in this dissertation assess and provide support for two main hypotheses: (1) Threat makes people more closed-minded, which in turn leads them to gravitate toward political conservatism; and (2) When people experience threat, they will be more likely to adhere to political ideologies that are characterized by certainty and control, both of which are primary hallmarks of conservatism.