Simplify the following text for a Grade 12 native English-speaking person.
Original: IQ scores have been shown to be associated with such factors as morbidity and mortality , parental social status , and , to a substantial degree , parental IQ .
Simplified: It could be shown that IQ scores have an association with other factors , such as morbidity and mortality , the social status of the parents , and to a big degree , parental IQ .