Twins often display amazing abilities - but is it telepathy?

Close siblings, especially identical twins, often have an uncanny ability to know what the other is thinking. They read their twin's emotions accurately, collaborate seamlessly on group tasks, and may even complete each other's sentences. Some anecdotes seem so outlandish, it's difficult to see how they could arise from any known physical or psychological process - sometimes knowing exactly what the other is thinking or sensing that the other is injured or distraught, even though the twins are hundreds of miles apart. What could account for these amazing tales? One ability that has been commonly attributed to identical twins is telepathy, the ability to sense the emotions or thoughts of others at a distance without any apparent interaction. Identical twins form from a single fertilized zygote that splits to form two developing embryos. Therefore, they share the same DNA down to the biochemistry of their brains and bodies. However, this only addresses the physiological and psychological similarities that twins often share - personality traits, skills, and afflictions. It is not obvious how twins might share this special mental link. Parapsychologists - psychologists who study phenomena outside the realm of traditional psychology - have attempted to find proof of telepathy since the latter decades of the 19th Century to no avail. In fact, not a single study or methodology has been able to confirm preternatural abilities such as telepathy in a manner that is both convincing and repeatable. This speaks to the inscrutable nature of such phenomena; they elude scientific analysis, and the vast majority of scientists claim that they don't exist at all, that parapsychology is chasing the metaphorical rainbow. However, just because something can't currently be studied in a rigorous scientific fashion doesn't make it nonexistent, and future breakthroughs could always bring these phenomena into the fold of mainstream science. For instance, the idea that dogs and cats could sense natural disasters such as earthquakes was dismissed as foolishness until relatively recently, whereas recent evidence indicates that these animals are more sensitive to subsonic frequencies than are humans, which can help them sense subtle vibrations that humans are not aware of. While we cannot dismiss the claims of twin telepathy outright, due to the overwhelming lack of evidence in parapsychology, it is advisable to look for a more mundane explanation for twins' seeming abilities. One such possibility is that twins are sensitized to the appearance, emotions, and even odor of each other - that is to say, subtle but observable differences become obvious to them. This phenomenon is sometimes also seen in close siblings, spouses, and friends. Another possible explanation is confirmation bias: if we expect to see a link between twins, we consider corroborating evidence as proof, ignoring the thousands of instances where twins fail to show any telepathic ability. Ultimately, the scientific consensus is that twins do not possess telepathy or any other abilities beyond the ken of modern analysis. However, the anecdotal evidence is profuse and sometimes too incredible to be accounted for by this explanation. Whether this reflects a shortcoming of science or credulity on the part of telepathy proponents is currently unknown.