Limitations of I Function in TwinsIdentical, Siamese, and half-twins are all examples of intrinsic variability in humans. Intrinsic variability exists in all animals and is an adaptive mechanism built into the nervous system in response to input. This mechanism allows humans to distinguish the same inputs as different from each other and, therefore, the possible outputs vary over time. It is possible that due to identical genetic input, twins share identical neural pathways and identical I functions. This hypothesis could explain the identical behaviors and the interdependence of feelings and thoughts that twins share. The differences observed in the twins' behaviors could simply be due to intrinsic variability leading to different outcomes or behaviors. During ovulation, when a woman releases an egg, three different processes can occur. First, the egg may remain in one piece all the way to the uterus where, if not fertilized, it will be expelled from the body along with the unused endometrium. Second, the egg, if fertilized, can develop into a single embryo, which is the most common type of pregnancy in humans, with approximately 99% of all births being singleton births (1). Finally, the egg can split into two separate halves, giving rise to genetically identical twins. The three types of twins mentioned previously are identical and are created when the fertilized egg separates into two complete and identical, joined parts, which results from one fertilized egg not completing the equal separation, resulting in the fusion of two fetuses one way or another. , and half-twins or polar body twins, which are formed when an unfertilized egg divides into two complete, identical parts and is then fertilized by two different sperm. The frequency of identical twins is 3.5 per 100 births (1) and the frequency of conjoined twins is 1 per 50,000 births, with only 100 known cases surviving their first year (5). There is no scientific explanation as to why an egg splits in two or two. more parts. It has been observed that egg division can be hereditary but can also occur spontaneously. This unexplained spontaneity or divergence from normal egg growth and fertilization could be due to intrinsic variability. This intrinsic variability could also be linked to certain behavioral differences between two genetically and culturally identical twins. Ideally, one could say that twins with identical genetic information and environments would have extremely similar, if not identical, neural pathways and central pattern generators (CPGs)..).