Final answer:
Twin studies are the method that best isolates the effects of genetics and experience on traits, by comparing the similarities between identical twins raised apart and together, and contrasting these with fraternal twins.
Step-by-step explanation:
The research method that allows researchers to most easily isolate the effect of both genetics and experience on specific traits is twin studies. Twin studies are particularly powerful because they can compare identical twins, who share 100% of their genes, with fraternal twins, who share only about 50% of their genes, similar to any siblings. When these sets of twins are raised apart, the comparison provides researchers with a unique opportunity to measure the impact of genetics versus the environment on various traits.
The findings from twin studies, such as the Minnesota Study of Twins Reared Apart, have indicated significant heritability for certain personality traits, suggesting a greater role of genetics in these aspects. However, it's critical to understand that traits are influenced by a complex interplay of multiple genes and environmental conditions, rather than being solely determined by genetics.