Herbert Spencer (1820–1903) was born in the industrial town of Derby, England, and was tutored first by his father, who was a schoolmaster, and later by his uncle. He never received a formal education. At age 17, Spencer went to work for the railroad and for the next 10 years held jobs ranging from surveyor to engineer. In 1848 he gained employment in London as a journalist—first as a junior—notes that it was Spencer then who introduced the term intelligence as it is used in modern psychology.
In his explanation of how associations are formed, Spencer relied heavily on the principle of contiguity. Environmental events that occur both simultaneously or in close succession are recorded in the brain and give rise to ideas of those events. Through the process of contiguity, our ideas come to map environmental events. However, for Spencer, the principle of contiguity alone was not adequate to explain why some behaviors persist whereas others do not. To explain the differential persistence of various behaviors, Spencer accepted Bain’s explanation of voluntary behavior. Spencer said, “On the recurrence of the circumstances, these muscular movements that were followed by success are likely to be repeated; what was at first an accidental combination of motions will now be a combination having considerable probability”. Spencer placed Bain’s observation within the context of evolutionary theory by asserting that a person persists in behaviors that are conducive to survival (those that cause pleasant feelings) and abstain from those that are not (those that cause painful feelings).