In summary, gender-related differences in mathematics performance do not exist in the general population, but differences do appear in selected groups. Among students, girls and boy do not differ in mathematics performance until high junior school. At this time, boys begin to show higher than average levels of math performance and confidence, and these differences persist throughout adulthood, at least for European American students in the United States. Studies of gifted children have shown that extraordinary mathematics performance is much more common among boys than girls, although this level of ability is rare even in boys. Such math talent may be the result of innate ability but may also be influenced by cultural expectations and parental encouragement.