Which has a greater influence nature or nurture?
Also question is, which has the greatest effect on intelligence nature or nurture?
Both have a great effect; nature is the factor that controls what kind of intelligence you'll be learning and the tools you'll receive to learn it. Nurture is also a factor because those who receive extra care as a child are known to be more intelligent and bright.
Just so, how does nature and nurture influence human behavior?
The nature versus nurture debate involves whether human behavior is determined by the environment, either prenatal or during a person's life, or by a person's genes. Nurture is generally taken as the influence of external factors after conception e.g. the product of exposure, experience and learning on an individual.
Like most aspects of human behavior and cognition, intelligence is a complex trait that is influenced by both genetic and environmental factors. Intelligence is challenging to study, in part because it can be defined and measured in different ways.