A researcher raises a sample of unrelated macaque monkeys in identical laboratory environments. He finds significant differences among these monkeys in their preference for novel visual stimuli. What might the researcher legitimately conclude concerning the relative effects of nature and nurture on the preference for visual novelty?

nature contributes substantially to the monkey's preference for visual novelty

Explanation:

In a nature versus nurture research, the researchers aims at studying the effect of genetics (nature) versus environment (nurture) on a particular behavior of the subjects. Nature asserts that the behavior and preferences of a subject is majorly determined by genetic make-up while nurture asserts that the behavior and preferences of a subject is determined by the environment which he grew in.

In study of monkeys kept under similar conditions showing different preferences, can only be explained that the environment which is homogeneous in this case did not play affect their behaviors and preferences but that genetics plays a more substantial role in their preferences  

answer; the trial de novo