What would it be like to have a twin? This is a question that people often ponder. People often say they see someone who looks like someone they already know. “Twin” comes from the German word “twine” which means “two together”. Most people automatically think of two people who look alike when they hear the word “twin.” However, there's more to twins than just looking alike. Twins are the most common type of multiple births. Many think that there are only two types of twins, identical and fraternal, often leaving out conjoined twins. Twins are truly unique and fascinating individuals due to their similarities on a biological, physical and psychological level. Early in each twin's life they begin to realize that there is another person who is part of their life, forever, who is just as important as them, their twin. They begin to strive to achieve their goals and achievements for the rest of their lives with a loyal friend and loving companions, trustingly sharing their deepest secrets. Not just twins of friends who will stand side by side until the end of time. A sister or brother who is so close to each other that no matter where they go or how far apart they are, they will always be by each other's side and in each other's hearts. As children they are very likely to remain together until adulthood. Separating twins is a very difficult task, not only for parents and teachers, but above all for themselves. Twins' lack of separation can cause them to isolate themselves from other children and adults. They also begin to communicate with each other in a symbolic way and this can disrupt their learning abilities in subjects such as English, reading and writing. Separating twins can give them a better look at life and how to interact or socialize with other people. Twins should most likely stay together if preferred, but separated from time to time. As twin individuals age, there are questions about whether they will stay together or separate from each other. Identical twins, being more identical in composition, abilities and interests, will be more likely to stay together than fraternal twins. Over time, psychologists have debated whether only our genes control our behaviors in life or whether the environment and people around us have any effect on our lives.