Simplify the following text for a Grade 10 native English-speaking person.
Original: During this work , he developed a scale measuring sexual orientation , now known as the Kinsey Scale which ranges from 0 to 6 , where 0 is exclusively heterosexual and 6 is exclusively homosexual ; a rating of X , for asexual , was added later by Kinsey 's associates .
Simplified: He developed the Kinsey Scale to measure sexual orientation . On one end of the scale , at the value 0 , the individual is entirely heterosexual .