Although twins share many characteristics, the fingerprint is not one of them. This is because the fingerprint patterns are not fully determined by the information in the genes, which is shared by identical twins.
One of the environmental factors that determine the shape of the fingerprint are intrauterine forces, for example that exerted by amniotic flow around the fetus during the gestation period, and that determines the pattern of the fingertips and hands. . As each sibling occupies a different position in the uterus, the intrauterine forces are different and as a result their fingerprint pictures, although they look alike, are unique. Other factors that can determine the pattern are variations in the concentration of some hormones and growth factors during pregnancy.
