A MALE’S ARMS ARE ALWAYS LONGER THAN THE ARMS OF A FEMALE WHEN HELD TO THE BODY, SO IF YOU MEASURE A WOMAN'S ARMS DANGLING FROM THE SIDE, THE CROTCH SHOULD STOP INSIDE THE PALMS OF HER HANDS WHILE FOR A MAN HIS CROTCH SHOULD STOP ABOVE HIS WRIST OR AT THE WRIST, THIS IS THE REASON A FEMALE WILL HAVE A SHORTER REACH WITH A MALE OF THE SAME HEIGHT.
BECAUSE OF THE LONGER COLLARBONE AND SHOULDERS THAT MALES HAVE, THIS CAUSES THE MALES MUSCLES AROUND THE NECK AND TRAPEZIUS MUSCLES TO BE MORE DEVELOPED MUCH MORE THAN FEMALES, SO MALES WILL HAVE STRONGER AND LARGER NECKS AND MORE DEFINED TRAPEZIUS MUSCLES THAN FEMALES

ALSO THE TRAPEZIUS MUSCLES OF THE MAN END ABRUPTLY AND THERE IS SEPARATION FROM WHERE IT ENDS TO WHERE THE SHOULDERS EXTEND WHILE IN WOMEN THE TRAP MUSCLES ENDS WHERE THE SHOULDER BEGINS, SEE DIAGRAM BELOW

MALES HAVE A WIDER NECK THAT HAS MASS AND FEMALES DO NOT, WHEN LOOKING FOR A MALE OF FEMALE NECK, LOOK FOR MASS IN THE NECK AND TRAPEZIUS MUSCLE TO DETERMINE IF THE PERSON IS MALE OR FEMALE.