What did Arthur Jensen conclude about intelligence based on his research?

Intelligence or IQ of a person is dependent on his genetic background.

Explanation:

Sir Arthur Jensen was a great psychologist of America. He was popular for his studies on genetics and intelligence of human population. He did a research in his lifetime on the relationship between the Intelligence Quotient and the genetic background of the person.

And this resulted in a result which showed that about 80% of the variation in IQ of a population is dependent on the genetic background. Rest 20 % is dependent on several factors like surrounding behavior, economic background, literacy etc.