ELI5: Psychological Biases Deviating Voting System Purpose

Voting systems often don't work as intended because human psychology intervenes. People are influenced by cognitive biases like the 'spoiler effect' (fearing their vote for a minor candidate will inadvertently help a less preferred major candidate win, leading them to vote 'strategically' rather than for their true preference). The 'bandwagon effect' can make people vote for who they perceive will win. 'Confirmation bias' means people seek out information that confirms their existing views, making them less open to alternative perspectives. These biases, combined with system design (e.g., 'first past the post'), can lead to outcomes that don't truly reflect the collective will or intended purpose of the system.