survival of the fittest

the tendency of individuals that are better adapted to a particular environment to be more successful at surviving and producing offspring. This concept is inherent in the theory of evolution by natural selection, as proposed in the 1850s by British naturalists Charles Darwin and Alfred Russel Wallace (1823–1913). See also competition for resources; Darwinian fitness; social Darwinism. [coined by Herbert Spencer in Principles of Biology (1864) and adopted by Darwin as a synonym for natural selection in the fifth edition of his Origin of Species (1869, Chapter 4)]

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Psychology term of the day

May 9th 2024

x-intercept

x -intercept

n. in an equation representing a straight-line relationship between two variables, the value of variable x when the value of variable y equals zero. For example, in the general linear equation format x = a + by, a represents the x-intercept.