One of the correct ways of selecting and directing the youth toward the right athletic activity is assessing their inherited physical and motor characteristics. The Scope of this study was to compare the physical characteristics (height, weight and max heart rate), physical fitness factors (max aerobic capacity, flexibility, abdominal muscle endurance and grip strength), motor fitness factors (Speed, agility and auditory response time), among 16 pairs of identical twin sisters (Experimental group), and 18 pairs of non -identical twin sisters (Control group), from the city of Rashet with an age range of 14-17 years.
Both contort and experimental groups were selected randomly and non -randomly based on specific criteria such as being monozygotic (MZ) or not under the supervision of a specialist. All Variables were investigated under similar condition, using standard and common field tests. The hypothesis of this study was also investigated by using Pearson coefficient correlation, dependent and independent (t) test with (α=0/05), using Spss program.