Final answer:
Samuel George Morton's research faced criticism due to biased methodologies, inconsistent measurement techniques, and preconceived notions of racial superiority that affected the validity of his conclusions.
Step-by-step explanation:
The issues with Samuel George Morton's research primarily revolve around his biased methodologies and the scientifically unsupported conclusions he drew regarding racial differences. Morton, a 19th-century American physician, collected and measured human skulls in an attempt to study the relationships between brain size and race. Critics have pointed out that Morton's collection methods were flawed, his measurement techniques were inconsistent, and he harbored preconceived notions about racial superiority that tainted his results. This controversy over his work is an example of the difficulties that can arise when scientific research is influenced by societal prejudices and the importance of objective, rigorous methodologies in producing reliable scientific knowledge.