Shazad and her twin brother, Amir, have recently turned 13 years old. Over the past year, family and friends recognize that Shazad has become more impulsive and easily loses her temper; Amir, on the other hand, loses his temper less frequently but has become more aggressive overall. What are some physical changes that males and females experience during puberty that may account for their behavior? What are some emotional and hormonal changes that males and females experience during puberty that may account for their behavior?