What is "bicameralism"

n. The principle of dividing legislative bodies into two groups with complementary powers and limitations designed to provide checks and balances against one another.

A bicameral legislature is one in which the legislators are divided into two separate assemblies, chambers or houses. Bicameralism is distinguished from unicameralism, in which all of the members deliberate and vote as a single group, and from some legislatures which have three or more separate assemblies, chambers or houses. As of 2015, somewhat less than half of the world's national legislatures are bicameral.

Often, the members of the two chambers are elected or selected using different methods, which vary from country to country. Enactment of primary legislation often requires a concurrent majority, the approval of a majority of members in each of the chambers of the legislature. However, in many Westminster system parliaments, the house to which the executive is responsible can overrule the other house.

Bicameralism is an essential and defining feature of the classical notion of mixed government.

Bicameralism (the philosophy of "two-chamberedness") is a hypothesis in psychology that argues that the human mind once assumed a state in which cognitive functions were divided between one part of the brain which appears to be "speaking", and a second part which listens and obeys—a bicameral mind. The term was coined by Julian Jaynes, who presented the idea in his 1976 book The Origin of Consciousness in the Breakdown of the Bicameral Mind, wherein he made the case that a bicameral mentality was the normal and ubiquitous state of the human mind as recently as 3000 years ago.

The Origin of Consciousness was financially successful, and has been reprinted several times. Originally published in 1976 (ISBN 0-395-20729-0), it was nominated for the National Book Award in 1978. It has been translated into Italian, Spanish, German, French, and Persian. A new edition, with an afterword that addressed some criticisms and restated the main themes, was published in the US in 1990 and in the UK by Penguin Books in 1993 (ISBN 0-14-017491-5), re-issued in 2000.

Bicameralism may refer to:

• Bicameralism, a form of legislature
• Bicameralism (psychology) a theory about the development of the human brain
• For bicameral script, see Letter case