The study also said that half of all differences in intelligence seem to stem from differences in genetic variations, researchers said.
Past research suggested that intelligent parents breed intelligent children, stirring feelings of anger and pride in many.
No one gene variant has been linked with intelligence.
Researchers compared almost 550,000 of these variations known as single nucleotide polymorphisms using tests of general intelligence in 3,500 unrelated adults. One tested problem-solving skills while the other tested acquired knowledge such as vocabulary.
Genetic variations could explain half of all differences in intelligence. Some combinations of these variants seemed to show up more frequently in more intelligent people.
"We have found gene signals associated with cognitive abilities," researcher Ian Deary told LiveScience. Deary also said that "The likelihood is that there are very many genes contributing, each with a small effect."
"We are not saying that intelligence is 'fixed' or 'determined' in our genes," researcher Peter Visscher told LiveScience. "We are saying that about 50 percent of individual differences between people in intelligence is due to genetics. We are not saying that the environment is unimportant," he added.