Final answer:
Herbert Spencer developed the concept of 'survival of the fittest' and contributed to the ideology of social Darwinism, which applies the concept of natural selection to human societies.
Step-by-step explanation:
Herbert Spencer was an English philosopher, anthropologist, and sociologist who developed the concept of "survival of the fittest." This term was used to describe the process of natural selection as outlined by Charles Darwin but Spencer extended it to include societal evolution. Critics have argued that the application of this concept to society, known as social Darwinism, mistakenly attributed societal success to inherent racial or ethnic traits, rather than recognizing the impact of unequal opportunities.
Spencer's views influenced the development of sociology and many of his ideas were adopted by William Graham Sumner and others, although the concept of social Darwinism has since been largely discredited. It is important to note that Darwin himself did not propose social Darwinism; it was Spencer's extension of Darwin's biological theories to the social realm that created this ideology.