Final answer:
The greatest difference in anatomical size between adolescents occurs between ages 12 and 15, coinciding with the adolescent growth spurt and the onset of puberty, which brings rapid physical, as well as cognitive and emotional, changes.
Step-by-step explanation:
Difference in Anatomical Size During Human Development
The difference in anatomical size between adolescents is greatest between ages 12 and 15 than at any other time in the human life span. This time period corresponds with the peak of the adolescent growth spurt (AGS), which includes rapid growth in height and weight along with significant changes in body composition and shape. While both boys and girls experience the AGS, it typically starts and peaks at slightly different ages. Girls usually begin puberty around ages 9 to 10, and boys between ages 11 and 12. Thus, the range from pre-adolescence to mid-adolescence is marked by these considerable physical transformations.
During puberty, which lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls, sexual maturation occurs and the body goes through significant changes. The brain, particularly the prefrontal cortex responsible for executive functions, also undergoes important developmental changes, although most significant cerebral size changes have occurred earlier.
Adolescence is characterized by not only physical changes but also cognitive, emotional, and social changes. Adolescence typically starts with the onset of puberty and continues into late teenage years, reaching adulthood around the age of 18. The exact ages can differ among individuals, but the most pronounced anatomical growth differences are observed in early to mid-adolescence, approximately between ages 12 and 15.