Psychological evaluation
Modern "Psychological evaluation" has been around for roughly 200 years, with roots that stem as far back as 2200 B.C. It started in China, and many psychologists throughout Europe worked to develop methods of testing into the 1900s. The first tests focused on aptitude. Eventually scientists tried to gauge mental processes in patients with brain damage, then children with special needs.
Pediatric psychology
The "official" history of pediatric psychology dates to 1968 when the Society of Pediatric Psychology was established within the American Psychological Association. However, its origins date back to the early 1900s and Lightner Witmer. Often considered the father of clinical psychology, Witmer spent a good deal of his time working in tandem with physicians to improve children's behaviors. Considering the roughly 70 years between Witmer and the formation of the SPP, this merging of medicine and psychology was a slow progression.